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Problem to show logs in task managers

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Ana M. Martinez

Problem to show logs in task managers

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Till Rohrmann

Re: Problem to show logs in task managers

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Ana M. Martinez

Re: Problem to show logs in task managers

Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}

On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Till Rohrmann

Re: Problem to show logs in task managers

In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till

On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:

Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Ana M. Martinez

Re: Problem to show logs in task managers

Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana

On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Till Rohrmann

Re: Problem to show logs in task managers

I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till

On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:

Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Ana M. Martinez

Re: Problem to show logs in task managers

Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):

1) Enable log aggregation in yarn-site:

https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana

On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

rmetzger0

Re: Problem to show logs in task managers

Maybe the isConverged() method is never called? For making that sure, just throw a RuntimeException inside the method to see whats happening.

On Wed, Jan 6, 2016 at 3:58 PM, Ana M. Martinez <[hidden email]> wrote:

Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Ana M. Martinez

Re: Problem to show logs in task managers

In reply to this post by Ana M. Martinez

Thanks for the tip Robert! It was a good idea to rule out other possible causes, but I am afraid that is not the problem. If we stick to the WordCountExample (for simplicity), the Exception is thrown if placed into the flatMap function.

I am going to try to re-write my problem and all the settings below:

When I try to aggregate all logs:

$yarn logs -applicationId application_1452250761414_0005

the following message is retrieved:

16/01/08 13:32:37 INFO client.RMProxy: Connecting to ResourceManager at 
ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

/var/log/hadoop-yarn/apps/hadoop/logs/application_1452250761414_0005does not exist.

Log aggregation has not completed or is not enabled.

(Tried the same command a few minutes later and got the same message, so might it be that log aggregation is not properly enabled??)

I am going to carefully enumerate all the steps I have followed (and settings) to see if someone can identify why the Logger messages from CORE nodes (in an Amazon cluster) are not shown.

1) Enable yarn.log-aggregation-enable property to true in /etc/alternatives/hadoop-conf/yarn-site.xml.

2) Include log messages in my WordCountExample as follows:

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        
        logger.info("Entering application.");

        DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.writeAsText(“output.txt", FileSystem.WriteMode.OVERWRITE);


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);
        
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
		for (String word : line.split(" ")) {
    			out.collect(new Tuple2<String, Integer>(word, 1));
    			//throw new RuntimeException("LineSplitter class called");
		}

        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("TestClass.class");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}

3) Start a yarn-cluster and execute my program with the following command:

$./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c eu.amidst.flinklink.examples.WordCountExample ../flinklink.jar

4) The output in the log folder is as follows:

13:31:04,945 INFO  org.apache.flink.client.CliFrontend                           - --------------------------------------------------------------------------------

13:31:04,947 INFO  org.apache.flink.client.CliFrontend                           -  Starting Command Line Client (Version: 0.10.0, Rev:ab2cca4, Date:10.11.2015 @ 13:50:14 UTC)

13:31:04,947 INFO  org.apache.flink.client.CliFrontend                           -  Current user: hadoop

13:31:04,947 INFO  org.apache.flink.client.CliFrontend                           -  JVM: OpenJDK 64-Bit Server VM - Oracle Corporation - 1.8/25.65-b01

13:31:04,947 INFO  org.apache.flink.client.CliFrontend                           -  Maximum heap size: 3344 MiBytes

13:31:04,947 INFO  org.apache.flink.client.CliFrontend                           -  JAVA_HOME: /etc/alternatives/jre

13:31:04,950 INFO  org.apache.flink.client.CliFrontend                           -  Hadoop version: 2.6.0

13:31:04,950 INFO  org.apache.flink.client.CliFrontend                           -  JVM Options:

13:31:04,950 INFO  org.apache.flink.client.CliFrontend                           -     -Dlog.file=/home/hadoop/flink-0.10.0/log/flink-hadoop-client-ip-172-31-33-221.log

13:31:04,950 INFO  org.apache.flink.client.CliFrontend                           -     -Dlog4j.configuration=file:/home/hadoop/flink-0.10.0/conf/log4j-cli.properties

13:31:04,950 INFO  org.apache.flink.client.CliFrontend                           -     -Dlogback.configurationFile=file:/home/hadoop/flink-0.10.0/conf/logback.xml

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -  Program Arguments:

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     run

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     -m

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     yarn-cluster

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     -yn

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     1

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     -ys

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     4

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     -yjm

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     1024

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     -ytm

13:31:04,951 INFO  org.apache.flink.client.CliFrontend                           -     1024

13:31:04,952 INFO  org.apache.flink.client.CliFrontend                           -     -c

13:31:04,952 INFO  org.apache.flink.client.CliFrontend                           -     eu.amidst.flinklink.examples.WordCountExample

13:31:04,952 INFO  org.apache.flink.client.CliFrontend                           -     ../flinklink.jar

13:31:04,952 INFO  org.apache.flink.client.CliFrontend                           - --------------------------------------------------------------------------------

13:31:04,954 INFO  org.apache.flink.client.CliFrontend                           - Using configuration directory /home/hadoop/flink-0.10.0/conf

13:31:04,954 INFO  org.apache.flink.client.CliFrontend                           - Trying to load configuration file

13:31:05,193 INFO  org.apache.flink.client.CliFrontend                           - Running 'run' command.

13:31:05,201 INFO  org.apache.flink.client.CliFrontend                           - Building program from JAR file

13:31:05,326 INFO  org.apache.flink.client.CliFrontend                           - YARN cluster mode detected. Switching Log4j output to console

13:31:05,385 INFO  org.apache.hadoop.yarn.client.RMProxy                         - Connecting to ResourceManager at
ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

13:31:05,534 INFO  org.apache.flink.client.FlinkYarnSessionCli                   - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.FlinkYarnClient to locate the jar

13:31:05,545 INFO  org.apache.flink.yarn.FlinkYarnClient                         - Using values:

13:31:05,547 INFO  org.apache.flink.yarn.FlinkYarnClient                         -
TaskManager count = 1

13:31:05,547 INFO  org.apache.flink.yarn.FlinkYarnClient                         -
JobManager memory = 1024

13:31:05,547 INFO  org.apache.flink.yarn.FlinkYarnClient                         -
TaskManager memory = 1024

13:31:06,112 INFO  org.apache.flink.yarn.Utils                                   - Copying from file:/home/hadoop/flink-0.10.0/lib/flink-dist-0.10.0.jar to
<a href="hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar" class="">
hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar

13:31:06,843 INFO  org.apache.flink.yarn.Utils                                   - Copying from /home/hadoop/flink-0.10.0/conf/flink-conf.yaml to
<a href="hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml" class="">
hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml

13:31:06,857 INFO  org.apache.flink.yarn.Utils                                   - Copying from file:/home/hadoop/flink-0.10.0/conf/logback.xml to
<a href="hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml" class="">
hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml

13:31:06,869 INFO  org.apache.flink.yarn.Utils                                   - Copying from file:/home/hadoop/flink-0.10.0/conf/log4j.properties to
<a href="hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties" class="">
hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties

13:31:06,892 INFO  org.apache.flink.yarn.FlinkYarnClient                         - Submitting application master application_1452250761414_0005

13:31:06,917 INFO  org.apache.hadoop.yarn.client.api.impl.YarnClientImpl         - Submitted application application_1452250761414_0005

13:31:06,917 INFO  org.apache.flink.yarn.FlinkYarnClient                         - Waiting for the cluster to be allocated

13:31:06,919 INFO  org.apache.flink.yarn.FlinkYarnClient                         - Deploying cluster, current state ACCEPTED

13:31:07,920 INFO  org.apache.flink.yarn.FlinkYarnClient                         - Deploying cluster, current state ACCEPTED

13:31:08,922 INFO  org.apache.flink.yarn.FlinkYarnClient                         - Deploying cluster, current state ACCEPTED

13:31:09,924 INFO  org.apache.flink.yarn.FlinkYarnClient                         - Deploying cluster, current state ACCEPTED

13:31:10,925 INFO  org.apache.flink.yarn.FlinkYarnClient                         - YARN application has been deployed successfully.

13:31:10,929 INFO  org.apache.flink.yarn.FlinkYarnCluster                        - Start actor system.

13:31:11,412 INFO  akka.event.slf4j.Slf4jLogger                                  - Slf4jLogger started

13:31:11,472 INFO  Remoting                                                      - Starting remoting

13:31:11,698 INFO  Remoting                                                      - Remoting started; listening on addresses :[<a href="akka.tcp://flink@172.31.33.221:39464" class="">akka.tcp://flink@172.31.33.221:39464]

13:31:11,733 INFO  org.apache.flink.yarn.FlinkYarnCluster                        - Start application client.

13:31:11,737 INFO  org.apache.flink.client.CliFrontend                           - YARN cluster started

13:31:11,737 INFO  org.apache.flink.client.CliFrontend                           - JobManager web interface address

http://ip-172-31-33-221.us-west-2.compute.internal:20888/proxy/application_1452250761414_0005/

13:31:11,737 INFO  org.apache.flink.client.CliFrontend                           - Waiting until all TaskManagers have connected

13:31:11,748 INFO  org.apache.flink.yarn.ApplicationClient                       - Notification about new leader address
<a href="akka.tcp://flink@172.31.45.98:46965/user/jobmanager" class="">akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,752 INFO  org.apache.flink.client.CliFrontend                           - No status updates from the YARN cluster received so far. Waiting ...

13:31:11,752 INFO  org.apache.flink.yarn.ApplicationClient                       - Received address of new leader
<a href="akka.tcp://flink@172.31.45.98:46965/user/jobmanager" class="">akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,753 INFO  org.apache.flink.yarn.ApplicationClient                       - Disconnect from JobManager null.

13:31:11,757 INFO  org.apache.flink.yarn.ApplicationClient                       - Trying to register at JobManager
<a href="akka.tcp://flink@172.31.45.98:46965/user/jobmanager" class="">akka.tcp://flink@172.31.45.98:46965/user/jobmanager.

13:31:12,040 INFO  org.apache.flink.yarn.ApplicationClient                       - Successfully registered at the JobManager Actor[<a href="akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782" class="">akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782]

13:31:12,253 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:12,753 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:13,254 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:13,755 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:14,255 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:14,756 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:15,257 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:15,758 INFO  org.apache.flink.client.CliFrontend                           - TaskManager status (0/1)

13:31:16,258 INFO  org.apache.flink.client.CliFrontend                           - All TaskManagers are connected

13:31:16,264 INFO  org.apache.flink.client.program.Client                        - Starting client actor system

13:31:16,265 INFO  org.apache.flink.runtime.client.JobClient                     - Starting JobClient actor system

13:31:16,283 INFO  akka.event.slf4j.Slf4jLogger                                  - Slf4jLogger started

13:31:16,288 INFO  Remoting                                                      - Starting remoting

13:31:16,301 INFO  Remoting                                                      - Remoting started; listening on addresses :[<a href="akka.tcp://flink@127.0.0.1:45919" class="">akka.tcp://flink@127.0.0.1:45919]

13:31:16,302 INFO  org.apache.flink.runtime.client.JobClient                     - Started JobClient actor system at 127.0.0.1:45919

13:31:16,302 INFO  org.apache.flink.client.CliFrontend                           - Using the parallelism provided by the remote cluster (4). To use another parallelism, set it at the ./bin/flink client.

13:31:16,302 INFO  org.apache.flink.client.CliFrontend                           - Starting execution of program

13:31:16,303 INFO  org.apache.flink.client.program.Client                        - Starting program in interactive mode

13:31:16,313 INFO  eu.amidst.flinklink.examples.WordCountExample                 - Entering application.

13:31:16,342 INFO  TestClass.class                                               - Logger in TestClass

13:31:16,346 INFO  org.apache.flink.api.java.typeutils.TypeExtractor             - class eu.amidst.flinklink.examples.WordCountExample$TestClass is not a valid POJO type

13:31:16,376 INFO  org.apache.flink.client.CliFrontend                           - Program execution finished

13:31:16,384 INFO  akka.remote.RemoteActorRefProvider$RemotingTerminator         - Shutting down remote daemon.

13:31:16,386 INFO  akka.remote.RemoteActorRefProvider$RemotingTerminator         - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,408 INFO  akka.remote.RemoteActorRefProvider$RemotingTerminator         - Remoting shut down.

13:31:16,431 INFO  org.apache.flink.client.CliFrontend                           - Shutting down YARN cluster

13:31:16,431 INFO  org.apache.flink.yarn.FlinkYarnCluster                        - Sending shutdown request to the Application Master

13:31:16,432 INFO  org.apache.flink.yarn.ApplicationClient                       - Sending StopYarnSession request to ApplicationMaster.

13:31:16,568 INFO  org.apache.flink.yarn.ApplicationClient                       - Remote JobManager has been stopped successfully. Stopping local application client

13:31:16,570 INFO  org.apache.flink.yarn.ApplicationClient                       - Stopped Application client.

13:31:16,570 INFO  org.apache.flink.yarn.ApplicationClient                       - Disconnect from JobManager Actor[<a href="akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782" class="">akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782].

13:31:16,573 INFO  akka.remote.RemoteActorRefProvider$RemotingTerminator         - Shutting down remote daemon.

13:31:16,573 INFO  akka.remote.RemoteActorRefProvider$RemotingTerminator         - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,584 INFO  akka.remote.RemoteActorRefProvider$RemotingTerminator         - Remoting shut down.

13:31:16,595 INFO  org.apache.flink.yarn.FlinkYarnCluster                        - Deleting files in
<a href="hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005" class="">
hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005

13:31:16,596 INFO  org.apache.flink.yarn.FlinkYarnCluster                        - Application application_1452250761414_0005 finished with state FINISHED and final state SUCCEEDED at 1452259876445

13:31:16,747 INFO  org.apache.flink.yarn.FlinkYarnCluster                        - YARN Client is shutting down

You can see the log messages from the WordCountExample and TestClass classes. But I have problems to show the logger message (INFO) in the LineSplitter class. Presumably, because it is executed in the CORE nodes and node in the MASTER node (it all runs well in my local computer).

Any tips?

Ana

On 06 Jan 2016, at 15:58, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Till Rohrmann

Re: Problem to show logs in task managers

You’re right that the log statements of the LineSplitter are in the logs of the cluster nodes, because that’s where the LineSplitter code is executed. In contrast, you create a TestClass on the client when you submit the program. Therefore, you see the logging statement “Logger in TestClass” on the command line or in the cli log file.

So I would assume that the problem is Yarn’s log aggregation. Either your configuration is not correct or there are still some Yarn containers running after the Flink job has finished. Yarn will only show you the logs after all containers are terminated. Maybe you could check that. Alternatively, you can try to retrieve the taskmanager logs manually by going to the machine where your yarn container was executed. Then under hadoop/logs/userlogs you should find somewhere the logs.

Cheers,
Till

On Fri, Jan 8, 2016 at 3:50 PM, Ana M. Martinez <[hidden email]> wrote:

Thanks for the tip Robert! It was a good idea to rule out other possible causes, but I am afraid that is not the problem. If we stick to the WordCountExample (for simplicity), the Exception is thrown if placed into the flatMap function.
I am going to try to re-write my problem and all the settings below:

When I try to aggregate all logs:
$yarn logs -applicationId application_1452250761414_0005

the following message is retrieved:

16/01/08 13:32:37 INFO client.RMProxy: Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

/var/log/hadoop-yarn/apps/hadoop/logs/application_1452250761414_0005does not exist.

Log aggregation has not completed or is not enabled.

(Tried the same command a few minutes later and got the same message, so might it be that log aggregation is not properly enabled??)

I am going to carefully enumerate all the steps I have followed (and settings) to see if someone can identify why the Logger messages from CORE nodes (in an Amazon cluster) are not shown.

1) Enable yarn.log-aggregation-enable property to true in /etc/alternatives/hadoop-conf/yarn-site.xml.

2) Include log messages in my WordCountExample as follows:
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        
        logger.info("Entering application.");

        DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.writeAsText(“output.txt", FileSystem.WriteMode.OVERWRITE);


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);
        
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
		for (String word : line.split(" ")) {
    			out.collect(new Tuple2<String, Integer>(word, 1));
    			//throw new RuntimeException("LineSplitter class called");
		}
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("TestClass.class");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
3) Start a yarn-cluster and execute my program with the following command:
$./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c eu.amidst.flinklink.examples.WordCountExample ../flinklink.jar

4) The output in the log folder is as follows:

13:31:04,945 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Starting Command Line Client (Version: 0.10.0, Rev:ab2cca4, Date:10.11.2015 @ 13:50:14 UTC)

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Current user: hadoop

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JVM: OpenJDK 64-Bit Server VM - Oracle Corporation - 1.8/25.65-b01

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Maximum heap size: 3344 MiBytes

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JAVA_HOME: /etc/alternatives/jre

13:31:04,950 INFO org.apache.flink.client.CliFrontend - Hadoop version: 2.6.0

13:31:04,950 INFO org.apache.flink.client.CliFrontend - JVM Options:

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog.file=/home/hadoop/flink-0.10.0/log/flink-hadoop-client-ip-172-31-33-221.log

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog4j.configuration=file:/home/hadoop/flink-0.10.0/conf/log4j-cli.properties

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlogback.configurationFile=file:/home/hadoop/flink-0.10.0/conf/logback.xml

13:31:04,951 INFO org.apache.flink.client.CliFrontend - Program Arguments:

13:31:04,951 INFO org.apache.flink.client.CliFrontend - run

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -m

13:31:04,951 INFO org.apache.flink.client.CliFrontend - yarn-cluster

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yn

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ys

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 4

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yjm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ytm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,952 INFO org.apache.flink.client.CliFrontend - -c

13:31:04,952 INFO org.apache.flink.client.CliFrontend - eu.amidst.flinklink.examples.WordCountExample

13:31:04,952 INFO org.apache.flink.client.CliFrontend - ../flinklink.jar

13:31:04,952 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Using configuration directory /home/hadoop/flink-0.10.0/conf

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Trying to load configuration file

13:31:05,193 INFO org.apache.flink.client.CliFrontend - Running 'run' command.

13:31:05,201 INFO org.apache.flink.client.CliFrontend - Building program from JAR file

13:31:05,326 INFO org.apache.flink.client.CliFrontend - YARN cluster mode detected. Switching Log4j output to console

13:31:05,385 INFO org.apache.hadoop.yarn.client.RMProxy - Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

13:31:05,534 INFO org.apache.flink.client.FlinkYarnSessionCli - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.FlinkYarnClient to locate the jar

13:31:05,545 INFO org.apache.flink.yarn.FlinkYarnClient - Using values:

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager count = 1

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - JobManager memory = 1024

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager memory = 1024

13:31:06,112 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/lib/flink-dist-0.10.0.jar to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar

13:31:06,843 INFO org.apache.flink.yarn.Utils - Copying from /home/hadoop/flink-0.10.0/conf/flink-conf.yaml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml

13:31:06,857 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/logback.xml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml

13:31:06,869 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/log4j.properties to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties

13:31:06,892 INFO org.apache.flink.yarn.FlinkYarnClient - Submitting application master application_1452250761414_0005

13:31:06,917 INFO org.apache.hadoop.yarn.client.api.impl.YarnClientImpl - Submitted application application_1452250761414_0005

13:31:06,917 INFO org.apache.flink.yarn.FlinkYarnClient - Waiting for the cluster to be allocated

13:31:06,919 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:07,920 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:08,922 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:09,924 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:10,925 INFO org.apache.flink.yarn.FlinkYarnClient - YARN application has been deployed successfully.

13:31:10,929 INFO org.apache.flink.yarn.FlinkYarnCluster - Start actor system.

13:31:11,412 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:11,472 INFO Remoting - Starting remoting

13:31:11,698 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@172.31.33.221:39464]

13:31:11,733 INFO org.apache.flink.yarn.FlinkYarnCluster - Start application client.

13:31:11,737 INFO org.apache.flink.client.CliFrontend - YARN cluster started

13:31:11,737 INFO org.apache.flink.client.CliFrontend - JobManager web interface address http://ip-172-31-33-221.us-west-2.compute.internal:20888/proxy/application_1452250761414_0005/

13:31:11,737 INFO org.apache.flink.client.CliFrontend - Waiting until all TaskManagers have connected

13:31:11,748 INFO org.apache.flink.yarn.ApplicationClient - Notification about new leader address akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,752 INFO org.apache.flink.client.CliFrontend - No status updates from the YARN cluster received so far. Waiting ...

13:31:11,752 INFO org.apache.flink.yarn.ApplicationClient - Received address of new leader akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,753 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager null.

13:31:11,757 INFO org.apache.flink.yarn.ApplicationClient - Trying to register at JobManager akka.tcp://flink@172.31.45.98:46965/user/jobmanager.

13:31:12,040 INFO org.apache.flink.yarn.ApplicationClient - Successfully registered at the JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782]

13:31:12,253 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:12,753 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,254 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,755 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,255 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,756 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,257 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,758 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:16,258 INFO org.apache.flink.client.CliFrontend - All TaskManagers are connected

13:31:16,264 INFO org.apache.flink.client.program.Client - Starting client actor system

13:31:16,265 INFO org.apache.flink.runtime.client.JobClient - Starting JobClient actor system

13:31:16,283 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:16,288 INFO Remoting - Starting remoting

13:31:16,301 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@127.0.0.1:45919]

13:31:16,302 INFO org.apache.flink.runtime.client.JobClient - Started JobClient actor system at 127.0.0.1:45919

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Using the parallelism provided by the remote cluster (4). To use another parallelism, set it at the ./bin/flink client.

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Starting execution of program

13:31:16,303 INFO org.apache.flink.client.program.Client - Starting program in interactive mode

13:31:16,313 INFO eu.amidst.flinklink.examples.WordCountExample - Entering application.

13:31:16,342 INFO TestClass.class - Logger in TestClass

13:31:16,346 INFO org.apache.flink.api.java.typeutils.TypeExtractor - class eu.amidst.flinklink.examples.WordCountExample$TestClass is not a valid POJO type

13:31:16,376 INFO org.apache.flink.client.CliFrontend - Program execution finished

13:31:16,384 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,386 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,408 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,431 INFO org.apache.flink.client.CliFrontend - Shutting down YARN cluster

13:31:16,431 INFO org.apache.flink.yarn.FlinkYarnCluster - Sending shutdown request to the Application Master

13:31:16,432 INFO org.apache.flink.yarn.ApplicationClient - Sending StopYarnSession request to ApplicationMaster.

13:31:16,568 INFO org.apache.flink.yarn.ApplicationClient - Remote JobManager has been stopped successfully. Stopping local application client

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Stopped Application client.

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782].

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,584 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,595 INFO org.apache.flink.yarn.FlinkYarnCluster - Deleting files in hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005

13:31:16,596 INFO org.apache.flink.yarn.FlinkYarnCluster - Application application_1452250761414_0005 finished with state FINISHED and final state SUCCEEDED at 1452259876445

13:31:16,747 INFO org.apache.flink.yarn.FlinkYarnCluster - YARN Client is shutting down

You can see the log messages from the WordCountExample and TestClass classes. But I have problems to show the logger message (INFO) in the LineSplitter class. Presumably, because it is executed in the CORE nodes and node in the MASTER node (it all runs well in my local computer).

Any tips?

Ana
On 06 Jan 2016, at 15:58, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Ana M. Martinez

Re: Problem to show logs in task managers

Hi Till,

Thanks for that! I can see the "Logger in LineSplitter.flatMap” output if I retrieve the task manager logs manually (under /var/log/hadoop-yarn/containers/application_X/…). However that solution is not ideal when for instance I am using 32 machines for my mapReduce operations.

I would like to know why Yarn’s log aggregation is not working. Can you tell me how to check if there are some Yarn containers running after the Flink job has finished? I have tried:

hadoop job -list

but I cannot see any jobs there, although I am not sure that it means that there are not containers running...

Thanks,

Ana

On 08 Jan 2016, at 16:24, Till Rohrmann <[hidden email]> wrote:
You’re right that the log statements of the LineSplitter are in the logs of the cluster nodes, because that’s where the LineSplitter code is executed. In contrast, you create a TestClass on the client when you submit the program. Therefore, you see the logging statement “Logger in TestClass” on the command line or in the cli log file.

So I would assume that the problem is Yarn’s log aggregation. Either your configuration is not correct or there are still some Yarn containers running after the Flink job has finished. Yarn will only show you the logs after all containers are terminated. Maybe you could check that. Alternatively, you can try to retrieve the taskmanager logs manually by going to the machine where your yarn container was executed. Then under hadoop/logs/userlogs you should find somewhere the logs.

Cheers,
Till
On Fri, Jan 8, 2016 at 3:50 PM, Ana M. Martinez <[hidden email]> wrote:
Thanks for the tip Robert! It was a good idea to rule out other possible causes, but I am afraid that is not the problem. If we stick to the WordCountExample (for simplicity), the Exception is thrown if placed into the flatMap function.
I am going to try to re-write my problem and all the settings below:

When I try to aggregate all logs:
$yarn logs -applicationId application_1452250761414_0005

the following message is retrieved:

16/01/08 13:32:37 INFO client.RMProxy: Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

/var/log/hadoop-yarn/apps/hadoop/logs/application_1452250761414_0005does not exist.

Log aggregation has not completed or is not enabled.

(Tried the same command a few minutes later and got the same message, so might it be that log aggregation is not properly enabled??)

I am going to carefully enumerate all the steps I have followed (and settings) to see if someone can identify why the Logger messages from CORE nodes (in an Amazon cluster) are not shown.

1) Enable yarn.log-aggregation-enable property to true in /etc/alternatives/hadoop-conf/yarn-site.xml.

2) Include log messages in my WordCountExample as follows:
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        
        logger.info("Entering application.");

        DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.writeAsText(“output.txt", FileSystem.WriteMode.OVERWRITE);


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);
        
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
		for (String word : line.split(" ")) {
    			out.collect(new Tuple2<String, Integer>(word, 1));
    			//throw new RuntimeException("LineSplitter class called");
		}
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("TestClass.class");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
3) Start a yarn-cluster and execute my program with the following command:
$./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c eu.amidst.flinklink.examples.WordCountExample ../flinklink.jar

4) The output in the log folder is as follows:

13:31:04,945 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Starting Command Line Client (Version: 0.10.0, Rev:ab2cca4, Date:10.11.2015 @ 13:50:14 UTC)

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Current user: hadoop

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JVM: OpenJDK 64-Bit Server VM - Oracle Corporation - 1.8/25.65-b01

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Maximum heap size: 3344 MiBytes

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JAVA_HOME: /etc/alternatives/jre

13:31:04,950 INFO org.apache.flink.client.CliFrontend - Hadoop version: 2.6.0

13:31:04,950 INFO org.apache.flink.client.CliFrontend - JVM Options:

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog.file=/home/hadoop/flink-0.10.0/log/flink-hadoop-client-ip-172-31-33-221.log

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog4j.configuration=file:/home/hadoop/flink-0.10.0/conf/log4j-cli.properties

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlogback.configurationFile=file:/home/hadoop/flink-0.10.0/conf/logback.xml

13:31:04,951 INFO org.apache.flink.client.CliFrontend - Program Arguments:

13:31:04,951 INFO org.apache.flink.client.CliFrontend - run

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -m

13:31:04,951 INFO org.apache.flink.client.CliFrontend - yarn-cluster

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yn

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ys

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 4

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yjm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ytm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,952 INFO org.apache.flink.client.CliFrontend - -c

13:31:04,952 INFO org.apache.flink.client.CliFrontend - eu.amidst.flinklink.examples.WordCountExample

13:31:04,952 INFO org.apache.flink.client.CliFrontend - ../flinklink.jar

13:31:04,952 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Using configuration directory /home/hadoop/flink-0.10.0/conf

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Trying to load configuration file

13:31:05,193 INFO org.apache.flink.client.CliFrontend - Running 'run' command.

13:31:05,201 INFO org.apache.flink.client.CliFrontend - Building program from JAR file

13:31:05,326 INFO org.apache.flink.client.CliFrontend - YARN cluster mode detected. Switching Log4j output to console

13:31:05,385 INFO org.apache.hadoop.yarn.client.RMProxy - Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

13:31:05,534 INFO org.apache.flink.client.FlinkYarnSessionCli - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.FlinkYarnClient to locate the jar

13:31:05,545 INFO org.apache.flink.yarn.FlinkYarnClient - Using values:

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager count = 1

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - JobManager memory = 1024

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager memory = 1024

13:31:06,112 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/lib/flink-dist-0.10.0.jar to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar

13:31:06,843 INFO org.apache.flink.yarn.Utils - Copying from /home/hadoop/flink-0.10.0/conf/flink-conf.yaml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml

13:31:06,857 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/logback.xml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml

13:31:06,869 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/log4j.properties to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties

13:31:06,892 INFO org.apache.flink.yarn.FlinkYarnClient - Submitting application master application_1452250761414_0005

13:31:06,917 INFO org.apache.hadoop.yarn.client.api.impl.YarnClientImpl - Submitted application application_1452250761414_0005

13:31:06,917 INFO org.apache.flink.yarn.FlinkYarnClient - Waiting for the cluster to be allocated

13:31:06,919 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:07,920 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:08,922 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:09,924 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:10,925 INFO org.apache.flink.yarn.FlinkYarnClient - YARN application has been deployed successfully.

13:31:10,929 INFO org.apache.flink.yarn.FlinkYarnCluster - Start actor system.

13:31:11,412 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:11,472 INFO Remoting - Starting remoting

13:31:11,698 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@172.31.33.221:39464]

13:31:11,733 INFO org.apache.flink.yarn.FlinkYarnCluster - Start application client.

13:31:11,737 INFO org.apache.flink.client.CliFrontend - YARN cluster started

13:31:11,737 INFO org.apache.flink.client.CliFrontend - JobManager web interface address http://ip-172-31-33-221.us-west-2.compute.internal:20888/proxy/application_1452250761414_0005/

13:31:11,737 INFO org.apache.flink.client.CliFrontend - Waiting until all TaskManagers have connected

13:31:11,748 INFO org.apache.flink.yarn.ApplicationClient - Notification about new leader address akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,752 INFO org.apache.flink.client.CliFrontend - No status updates from the YARN cluster received so far. Waiting ...

13:31:11,752 INFO org.apache.flink.yarn.ApplicationClient - Received address of new leader akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,753 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager null.

13:31:11,757 INFO org.apache.flink.yarn.ApplicationClient - Trying to register at JobManager akka.tcp://flink@172.31.45.98:46965/user/jobmanager.

13:31:12,040 INFO org.apache.flink.yarn.ApplicationClient - Successfully registered at the JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782]

13:31:12,253 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:12,753 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,254 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,755 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,255 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,756 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,257 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,758 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:16,258 INFO org.apache.flink.client.CliFrontend - All TaskManagers are connected

13:31:16,264 INFO org.apache.flink.client.program.Client - Starting client actor system

13:31:16,265 INFO org.apache.flink.runtime.client.JobClient - Starting JobClient actor system

13:31:16,283 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:16,288 INFO Remoting - Starting remoting

13:31:16,301 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@127.0.0.1:45919]

13:31:16,302 INFO org.apache.flink.runtime.client.JobClient - Started JobClient actor system at 127.0.0.1:45919

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Using the parallelism provided by the remote cluster (4). To use another parallelism, set it at the ./bin/flink client.

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Starting execution of program

13:31:16,303 INFO org.apache.flink.client.program.Client - Starting program in interactive mode

13:31:16,313 INFO eu.amidst.flinklink.examples.WordCountExample - Entering application.

13:31:16,342 INFO TestClass.class - Logger in TestClass

13:31:16,346 INFO org.apache.flink.api.java.typeutils.TypeExtractor - class eu.amidst.flinklink.examples.WordCountExample$TestClass is not a valid POJO type

13:31:16,376 INFO org.apache.flink.client.CliFrontend - Program execution finished

13:31:16,384 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,386 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,408 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,431 INFO org.apache.flink.client.CliFrontend - Shutting down YARN cluster

13:31:16,431 INFO org.apache.flink.yarn.FlinkYarnCluster - Sending shutdown request to the Application Master

13:31:16,432 INFO org.apache.flink.yarn.ApplicationClient - Sending StopYarnSession request to ApplicationMaster.

13:31:16,568 INFO org.apache.flink.yarn.ApplicationClient - Remote JobManager has been stopped successfully. Stopping local application client

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Stopped Application client.

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782].

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,584 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,595 INFO org.apache.flink.yarn.FlinkYarnCluster - Deleting files in hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005

13:31:16,596 INFO org.apache.flink.yarn.FlinkYarnCluster - Application application_1452250761414_0005 finished with state FINISHED and final state SUCCEEDED at 1452259876445

13:31:16,747 INFO org.apache.flink.yarn.FlinkYarnCluster - YARN Client is shutting down

You can see the log messages from the WordCountExample and TestClass classes. But I have problems to show the logger message (INFO) in the LineSplitter class. Presumably, because it is executed in the CORE nodes and node in the MASTER node (it all runs well in my local computer).

Any tips?

Ana
On 06 Jan 2016, at 15:58, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Till Rohrmann

Re: Problem to show logs in task managers

Hi Ana,

good to hear that you found the logging statements. You can check in Yarn’s web interface whether there are still occupied containers. Alternatively you can go to the different machines and run jps which lists you the running Java processes. If you see an ApplicationMaster or YarnTaskManagerRunner process, then there is still a container running with Flink on this machine. I hope this helps you.

Cheers,
Till

On Mon, Jan 11, 2016 at 9:37 AM, Ana M. Martinez <[hidden email]> wrote:

Hi Till,

Thanks for that! I can see the "Logger in LineSplitter.flatMap” output if I retrieve the task manager logs manually (under /var/log/hadoop-yarn/containers/application_X/…). However that solution is not ideal when for instance I am using 32 machines for my mapReduce operations.

I would like to know why Yarn’s log aggregation is not working. Can you tell me how to check if there are some Yarn containers running after the Flink job has finished? I have tried:

hadoop job -list

but I cannot see any jobs there, although I am not sure that it means that there are not containers running...

Thanks,

Ana
On 08 Jan 2016, at 16:24, Till Rohrmann <[hidden email]> wrote:
You’re right that the log statements of the LineSplitter are in the logs of the cluster nodes, because that’s where the LineSplitter code is executed. In contrast, you create a TestClass on the client when you submit the program. Therefore, you see the logging statement “Logger in TestClass” on the command line or in the cli log file.

So I would assume that the problem is Yarn’s log aggregation. Either your configuration is not correct or there are still some Yarn containers running after the Flink job has finished. Yarn will only show you the logs after all containers are terminated. Maybe you could check that. Alternatively, you can try to retrieve the taskmanager logs manually by going to the machine where your yarn container was executed. Then under hadoop/logs/userlogs you should find somewhere the logs.

Cheers,
Till
On Fri, Jan 8, 2016 at 3:50 PM, Ana M. Martinez <[hidden email]> wrote:
Thanks for the tip Robert! It was a good idea to rule out other possible causes, but I am afraid that is not the problem. If we stick to the WordCountExample (for simplicity), the Exception is thrown if placed into the flatMap function.
I am going to try to re-write my problem and all the settings below:

When I try to aggregate all logs:
$yarn logs -applicationId application_1452250761414_0005

the following message is retrieved:

16/01/08 13:32:37 INFO client.RMProxy: Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

/var/log/hadoop-yarn/apps/hadoop/logs/application_1452250761414_0005does not exist.

Log aggregation has not completed or is not enabled.

(Tried the same command a few minutes later and got the same message, so might it be that log aggregation is not properly enabled??)

I am going to carefully enumerate all the steps I have followed (and settings) to see if someone can identify why the Logger messages from CORE nodes (in an Amazon cluster) are not shown.

1) Enable yarn.log-aggregation-enable property to true in /etc/alternatives/hadoop-conf/yarn-site.xml.

2) Include log messages in my WordCountExample as follows:
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        
        logger.info("Entering application.");

        DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.writeAsText(“output.txt", FileSystem.WriteMode.OVERWRITE);


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);
        
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
		for (String word : line.split(" ")) {
    			out.collect(new Tuple2<String, Integer>(word, 1));
    			//throw new RuntimeException("LineSplitter class called");
		}
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("TestClass.class");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
3) Start a yarn-cluster and execute my program with the following command:
$./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c eu.amidst.flinklink.examples.WordCountExample ../flinklink.jar

4) The output in the log folder is as follows:

13:31:04,945 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Starting Command Line Client (Version: 0.10.0, Rev:ab2cca4, Date:10.11.2015 @ 13:50:14 UTC)

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Current user: hadoop

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JVM: OpenJDK 64-Bit Server VM - Oracle Corporation - 1.8/25.65-b01

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Maximum heap size: 3344 MiBytes

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JAVA_HOME: /etc/alternatives/jre

13:31:04,950 INFO org.apache.flink.client.CliFrontend - Hadoop version: 2.6.0

13:31:04,950 INFO org.apache.flink.client.CliFrontend - JVM Options:

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog.file=/home/hadoop/flink-0.10.0/log/flink-hadoop-client-ip-172-31-33-221.log

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog4j.configuration=file:/home/hadoop/flink-0.10.0/conf/log4j-cli.properties

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlogback.configurationFile=file:/home/hadoop/flink-0.10.0/conf/logback.xml

13:31:04,951 INFO org.apache.flink.client.CliFrontend - Program Arguments:

13:31:04,951 INFO org.apache.flink.client.CliFrontend - run

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -m

13:31:04,951 INFO org.apache.flink.client.CliFrontend - yarn-cluster

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yn

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ys

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 4

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yjm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ytm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,952 INFO org.apache.flink.client.CliFrontend - -c

13:31:04,952 INFO org.apache.flink.client.CliFrontend - eu.amidst.flinklink.examples.WordCountExample

13:31:04,952 INFO org.apache.flink.client.CliFrontend - ../flinklink.jar

13:31:04,952 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Using configuration directory /home/hadoop/flink-0.10.0/conf

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Trying to load configuration file

13:31:05,193 INFO org.apache.flink.client.CliFrontend - Running 'run' command.

13:31:05,201 INFO org.apache.flink.client.CliFrontend - Building program from JAR file

13:31:05,326 INFO org.apache.flink.client.CliFrontend - YARN cluster mode detected. Switching Log4j output to console

13:31:05,385 INFO org.apache.hadoop.yarn.client.RMProxy - Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

13:31:05,534 INFO org.apache.flink.client.FlinkYarnSessionCli - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.FlinkYarnClient to locate the jar

13:31:05,545 INFO org.apache.flink.yarn.FlinkYarnClient - Using values:

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager count = 1

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - JobManager memory = 1024

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager memory = 1024

13:31:06,112 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/lib/flink-dist-0.10.0.jar to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar

13:31:06,843 INFO org.apache.flink.yarn.Utils - Copying from /home/hadoop/flink-0.10.0/conf/flink-conf.yaml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml

13:31:06,857 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/logback.xml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml

13:31:06,869 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/log4j.properties to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties

13:31:06,892 INFO org.apache.flink.yarn.FlinkYarnClient - Submitting application master application_1452250761414_0005

13:31:06,917 INFO org.apache.hadoop.yarn.client.api.impl.YarnClientImpl - Submitted application application_1452250761414_0005

13:31:06,917 INFO org.apache.flink.yarn.FlinkYarnClient - Waiting for the cluster to be allocated

13:31:06,919 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:07,920 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:08,922 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:09,924 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:10,925 INFO org.apache.flink.yarn.FlinkYarnClient - YARN application has been deployed successfully.

13:31:10,929 INFO org.apache.flink.yarn.FlinkYarnCluster - Start actor system.

13:31:11,412 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:11,472 INFO Remoting - Starting remoting

13:31:11,698 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@172.31.33.221:39464]

13:31:11,733 INFO org.apache.flink.yarn.FlinkYarnCluster - Start application client.

13:31:11,737 INFO org.apache.flink.client.CliFrontend - YARN cluster started

13:31:11,737 INFO org.apache.flink.client.CliFrontend - JobManager web interface address http://ip-172-31-33-221.us-west-2.compute.internal:20888/proxy/application_1452250761414_0005/

13:31:11,737 INFO org.apache.flink.client.CliFrontend - Waiting until all TaskManagers have connected

13:31:11,748 INFO org.apache.flink.yarn.ApplicationClient - Notification about new leader address akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,752 INFO org.apache.flink.client.CliFrontend - No status updates from the YARN cluster received so far. Waiting ...

13:31:11,752 INFO org.apache.flink.yarn.ApplicationClient - Received address of new leader akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,753 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager null.

13:31:11,757 INFO org.apache.flink.yarn.ApplicationClient - Trying to register at JobManager akka.tcp://flink@172.31.45.98:46965/user/jobmanager.

13:31:12,040 INFO org.apache.flink.yarn.ApplicationClient - Successfully registered at the JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782]

13:31:12,253 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:12,753 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,254 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,755 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,255 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,756 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,257 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,758 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:16,258 INFO org.apache.flink.client.CliFrontend - All TaskManagers are connected

13:31:16,264 INFO org.apache.flink.client.program.Client - Starting client actor system

13:31:16,265 INFO org.apache.flink.runtime.client.JobClient - Starting JobClient actor system

13:31:16,283 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:16,288 INFO Remoting - Starting remoting

13:31:16,301 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@127.0.0.1:45919]

13:31:16,302 INFO org.apache.flink.runtime.client.JobClient - Started JobClient actor system at 127.0.0.1:45919

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Using the parallelism provided by the remote cluster (4). To use another parallelism, set it at the ./bin/flink client.

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Starting execution of program

13:31:16,303 INFO org.apache.flink.client.program.Client - Starting program in interactive mode

13:31:16,313 INFO eu.amidst.flinklink.examples.WordCountExample - Entering application.

13:31:16,342 INFO TestClass.class - Logger in TestClass

13:31:16,346 INFO org.apache.flink.api.java.typeutils.TypeExtractor - class eu.amidst.flinklink.examples.WordCountExample$TestClass is not a valid POJO type

13:31:16,376 INFO org.apache.flink.client.CliFrontend - Program execution finished

13:31:16,384 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,386 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,408 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,431 INFO org.apache.flink.client.CliFrontend - Shutting down YARN cluster

13:31:16,431 INFO org.apache.flink.yarn.FlinkYarnCluster - Sending shutdown request to the Application Master

13:31:16,432 INFO org.apache.flink.yarn.ApplicationClient - Sending StopYarnSession request to ApplicationMaster.

13:31:16,568 INFO org.apache.flink.yarn.ApplicationClient - Remote JobManager has been stopped successfully. Stopping local application client

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Stopped Application client.

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782].

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,584 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,595 INFO org.apache.flink.yarn.FlinkYarnCluster - Deleting files in hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005

13:31:16,596 INFO org.apache.flink.yarn.FlinkYarnCluster - Application application_1452250761414_0005 finished with state FINISHED and final state SUCCEEDED at 1452259876445

13:31:16,747 INFO org.apache.flink.yarn.FlinkYarnCluster - YARN Client is shutting down

You can see the log messages from the WordCountExample and TestClass classes. But I have problems to show the logger message (INFO) in the LineSplitter class. Presumably, because it is executed in the CORE nodes and node in the MASTER node (it all runs well in my local computer).

Any tips?

Ana
On 06 Jan 2016, at 15:58, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Ana M. Martinez

Re: Problem to show logs in task managers

Hi Till,

Thanks for your help. I have checked both in Yarn’s web interface and through command line and it seems that there are not occupied containers.

Additionally, I have checked the configuration values in the web interface and even though I have changed the log.aggregation property in the yarn-site.xml file to true, it appears as false and with the following source label:

<property>

<name>yarn.log-aggregation-enable</name>
<value>false</value>
<source>java.io.BufferedInputStream@3c407114</source>

</property>

I am not sure if that is relevant. I had assumed that the "./bin/flink run -m yarn-cluster" command is starting a yarn session and thus reloading the yarn-site file. Is that right? If I am wrong here, then, how can I restart it so that the modifications in the yarn-site.xml file are considered? (I have also tried with ./bin/yarn-session.sh and then ./bin/flink run without success…).

I am not sure if this is related to flink anymore, should I move my problem to the yarn community instead?

Thanks,

Ana

On 11 Jan 2016, at 10:37, Till Rohrmann <[hidden email]> wrote:
Hi Ana,

good to hear that you found the logging statements. You can check in Yarn’s web interface whether there are still occupied containers. Alternatively you can go to the different machines and run jps which lists you the running Java processes. If you see an ApplicationMaster or YarnTaskManagerRunner process, then there is still a container running with Flink on this machine. I hope this helps you.

Cheers,
Till
On Mon, Jan 11, 2016 at 9:37 AM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Thanks for that! I can see the "Logger in LineSplitter.flatMap” output if I retrieve the task manager logs manually (under /var/log/hadoop-yarn/containers/application_X/…). However that solution is not ideal when for instance I am using 32 machines for my mapReduce operations.

I would like to know why Yarn’s log aggregation is not working. Can you tell me how to check if there are some Yarn containers running after the Flink job has finished? I have tried:

hadoop job -list

but I cannot see any jobs there, although I am not sure that it means that there are not containers running...

Thanks,

Ana
On 08 Jan 2016, at 16:24, Till Rohrmann <[hidden email]> wrote:
You’re right that the log statements of the LineSplitter are in the logs of the cluster nodes, because that’s where the LineSplitter code is executed. In contrast, you create a TestClass on the client when you submit the program. Therefore, you see the logging statement “Logger in TestClass” on the command line or in the cli log file.

So I would assume that the problem is Yarn’s log aggregation. Either your configuration is not correct or there are still some Yarn containers running after the Flink job has finished. Yarn will only show you the logs after all containers are terminated. Maybe you could check that. Alternatively, you can try to retrieve the taskmanager logs manually by going to the machine where your yarn container was executed. Then under hadoop/logs/userlogs you should find somewhere the logs.

Cheers,
Till
On Fri, Jan 8, 2016 at 3:50 PM, Ana M. Martinez <[hidden email]> wrote:
Thanks for the tip Robert! It was a good idea to rule out other possible causes, but I am afraid that is not the problem. If we stick to the WordCountExample (for simplicity), the Exception is thrown if placed into the flatMap function.
I am going to try to re-write my problem and all the settings below:

When I try to aggregate all logs:
$yarn logs -applicationId application_1452250761414_0005

the following message is retrieved:

16/01/08 13:32:37 INFO client.RMProxy: Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

/var/log/hadoop-yarn/apps/hadoop/logs/application_1452250761414_0005does not exist.

Log aggregation has not completed or is not enabled.

(Tried the same command a few minutes later and got the same message, so might it be that log aggregation is not properly enabled??)

I am going to carefully enumerate all the steps I have followed (and settings) to see if someone can identify why the Logger messages from CORE nodes (in an Amazon cluster) are not shown.

1) Enable yarn.log-aggregation-enable property to true in /etc/alternatives/hadoop-conf/yarn-site.xml.

2) Include log messages in my WordCountExample as follows:
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        
        logger.info("Entering application.");

        DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.writeAsText(“output.txt", FileSystem.WriteMode.OVERWRITE);


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);
        
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
		for (String word : line.split(" ")) {
    			out.collect(new Tuple2<String, Integer>(word, 1));
    			//throw new RuntimeException("LineSplitter class called");
		}
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("TestClass.class");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
3) Start a yarn-cluster and execute my program with the following command:
$./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c eu.amidst.flinklink.examples.WordCountExample ../flinklink.jar

4) The output in the log folder is as follows:

13:31:04,945 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Starting Command Line Client (Version: 0.10.0, Rev:ab2cca4, Date:10.11.2015 @ 13:50:14 UTC)

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Current user: hadoop

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JVM: OpenJDK 64-Bit Server VM - Oracle Corporation - 1.8/25.65-b01

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Maximum heap size: 3344 MiBytes

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JAVA_HOME: /etc/alternatives/jre

13:31:04,950 INFO org.apache.flink.client.CliFrontend - Hadoop version: 2.6.0

13:31:04,950 INFO org.apache.flink.client.CliFrontend - JVM Options:

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog.file=/home/hadoop/flink-0.10.0/log/flink-hadoop-client-ip-172-31-33-221.log

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog4j.configuration=file:/home/hadoop/flink-0.10.0/conf/log4j-cli.properties

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlogback.configurationFile=file:/home/hadoop/flink-0.10.0/conf/logback.xml

13:31:04,951 INFO org.apache.flink.client.CliFrontend - Program Arguments:

13:31:04,951 INFO org.apache.flink.client.CliFrontend - run

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -m

13:31:04,951 INFO org.apache.flink.client.CliFrontend - yarn-cluster

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yn

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ys

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 4

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yjm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ytm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,952 INFO org.apache.flink.client.CliFrontend - -c

13:31:04,952 INFO org.apache.flink.client.CliFrontend - eu.amidst.flinklink.examples.WordCountExample

13:31:04,952 INFO org.apache.flink.client.CliFrontend - ../flinklink.jar

13:31:04,952 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Using configuration directory /home/hadoop/flink-0.10.0/conf

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Trying to load configuration file

13:31:05,193 INFO org.apache.flink.client.CliFrontend - Running 'run' command.

13:31:05,201 INFO org.apache.flink.client.CliFrontend - Building program from JAR file

13:31:05,326 INFO org.apache.flink.client.CliFrontend - YARN cluster mode detected. Switching Log4j output to console

13:31:05,385 INFO org.apache.hadoop.yarn.client.RMProxy - Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

13:31:05,534 INFO org.apache.flink.client.FlinkYarnSessionCli - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.FlinkYarnClient to locate the jar

13:31:05,545 INFO org.apache.flink.yarn.FlinkYarnClient - Using values:

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager count = 1

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - JobManager memory = 1024

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager memory = 1024

13:31:06,112 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/lib/flink-dist-0.10.0.jar to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar

13:31:06,843 INFO org.apache.flink.yarn.Utils - Copying from /home/hadoop/flink-0.10.0/conf/flink-conf.yaml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml

13:31:06,857 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/logback.xml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml

13:31:06,869 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/log4j.properties to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties

13:31:06,892 INFO org.apache.flink.yarn.FlinkYarnClient - Submitting application master application_1452250761414_0005

13:31:06,917 INFO org.apache.hadoop.yarn.client.api.impl.YarnClientImpl - Submitted application application_1452250761414_0005

13:31:06,917 INFO org.apache.flink.yarn.FlinkYarnClient - Waiting for the cluster to be allocated

13:31:06,919 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:07,920 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:08,922 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:09,924 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:10,925 INFO org.apache.flink.yarn.FlinkYarnClient - YARN application has been deployed successfully.

13:31:10,929 INFO org.apache.flink.yarn.FlinkYarnCluster - Start actor system.

13:31:11,412 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:11,472 INFO Remoting - Starting remoting

13:31:11,698 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@172.31.33.221:39464]

13:31:11,733 INFO org.apache.flink.yarn.FlinkYarnCluster - Start application client.

13:31:11,737 INFO org.apache.flink.client.CliFrontend - YARN cluster started

13:31:11,737 INFO org.apache.flink.client.CliFrontend - JobManager web interface address http://ip-172-31-33-221.us-west-2.compute.internal:20888/proxy/application_1452250761414_0005/

13:31:11,737 INFO org.apache.flink.client.CliFrontend - Waiting until all TaskManagers have connected

13:31:11,748 INFO org.apache.flink.yarn.ApplicationClient - Notification about new leader address akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,752 INFO org.apache.flink.client.CliFrontend - No status updates from the YARN cluster received so far. Waiting ...

13:31:11,752 INFO org.apache.flink.yarn.ApplicationClient - Received address of new leader akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,753 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager null.

13:31:11,757 INFO org.apache.flink.yarn.ApplicationClient - Trying to register at JobManager akka.tcp://flink@172.31.45.98:46965/user/jobmanager.

13:31:12,040 INFO org.apache.flink.yarn.ApplicationClient - Successfully registered at the JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782]

13:31:12,253 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:12,753 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,254 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,755 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,255 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,756 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,257 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,758 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:16,258 INFO org.apache.flink.client.CliFrontend - All TaskManagers are connected

13:31:16,264 INFO org.apache.flink.client.program.Client - Starting client actor system

13:31:16,265 INFO org.apache.flink.runtime.client.JobClient - Starting JobClient actor system

13:31:16,283 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:16,288 INFO Remoting - Starting remoting

13:31:16,301 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@127.0.0.1:45919]

13:31:16,302 INFO org.apache.flink.runtime.client.JobClient - Started JobClient actor system at 127.0.0.1:45919

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Using the parallelism provided by the remote cluster (4). To use another parallelism, set it at the ./bin/flink client.

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Starting execution of program

13:31:16,303 INFO org.apache.flink.client.program.Client - Starting program in interactive mode

13:31:16,313 INFO eu.amidst.flinklink.examples.WordCountExample - Entering application.

13:31:16,342 INFO TestClass.class - Logger in TestClass

13:31:16,346 INFO org.apache.flink.api.java.typeutils.TypeExtractor - class eu.amidst.flinklink.examples.WordCountExample$TestClass is not a valid POJO type

13:31:16,376 INFO org.apache.flink.client.CliFrontend - Program execution finished

13:31:16,384 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,386 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,408 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,431 INFO org.apache.flink.client.CliFrontend - Shutting down YARN cluster

13:31:16,431 INFO org.apache.flink.yarn.FlinkYarnCluster - Sending shutdown request to the Application Master

13:31:16,432 INFO org.apache.flink.yarn.ApplicationClient - Sending StopYarnSession request to ApplicationMaster.

13:31:16,568 INFO org.apache.flink.yarn.ApplicationClient - Remote JobManager has been stopped successfully. Stopping local application client

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Stopped Application client.

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782].

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,584 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,595 INFO org.apache.flink.yarn.FlinkYarnCluster - Deleting files in hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005

13:31:16,596 INFO org.apache.flink.yarn.FlinkYarnCluster - Application application_1452250761414_0005 finished with state FINISHED and final state SUCCEEDED at 1452259876445

13:31:16,747 INFO org.apache.flink.yarn.FlinkYarnCluster - YARN Client is shutting down

You can see the log messages from the WordCountExample and TestClass classes. But I have problems to show the logger message (INFO) in the LineSplitter class. Presumably, because it is executed in the CORE nodes and node in the MASTER node (it all runs well in my local computer).

Any tips?

Ana
On 06 Jan 2016, at 15:58, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Till Rohrmann

Re: Problem to show logs in task managers

You have to restart the yarn cluster to let your changes take effect. You can do that via HADOOP_HOME/sbin/stop-yarn.sh; HADOOP_HOME/sbin/start-yarn.sh.

The commands yarn-session.sh ... and bin/flink run -m yarn cluster start a new yarn application within the yarn cluster.

Cheers,
Till

On Mon, Jan 11, 2016 at 1:39 PM, Ana M. Martinez <[hidden email]> wrote:

Hi Till,

Thanks for your help. I have checked both in Yarn’s web interface and through command line and it seems that there are not occupied containers.

Additionally, I have checked the configuration values in the web interface and even though I have changed the log.aggregation property in the yarn-site.xml file to true, it appears as false and with the following source label:

<property>

<name>yarn.log-aggregation-enable</name>

<value>false</value>

<source>java.io.BufferedInputStream@3c407114</source>

</property>

I am not sure if that is relevant. I had assumed that the "./bin/flink run -m yarn-cluster" command is starting a yarn session and thus reloading the yarn-site file. Is that right? If I am wrong here, then, how can I restart it so that the modifications in the yarn-site.xml file are considered? (I have also tried with ./bin/yarn-session.sh and then ./bin/flink run without success…).

I am not sure if this is related to flink anymore, should I move my problem to the yarn community instead?

Thanks,

Ana
On 11 Jan 2016, at 10:37, Till Rohrmann <[hidden email]> wrote:
Hi Ana,

good to hear that you found the logging statements. You can check in Yarn’s web interface whether there are still occupied containers. Alternatively you can go to the different machines and run jps which lists you the running Java processes. If you see an ApplicationMaster or YarnTaskManagerRunner process, then there is still a container running with Flink on this machine. I hope this helps you.

Cheers,
Till
On Mon, Jan 11, 2016 at 9:37 AM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Thanks for that! I can see the "Logger in LineSplitter.flatMap” output if I retrieve the task manager logs manually (under /var/log/hadoop-yarn/containers/application_X/…). However that solution is not ideal when for instance I am using 32 machines for my mapReduce operations.

I would like to know why Yarn’s log aggregation is not working. Can you tell me how to check if there are some Yarn containers running after the Flink job has finished? I have tried:

hadoop job -list

but I cannot see any jobs there, although I am not sure that it means that there are not containers running...

Thanks,

Ana
On 08 Jan 2016, at 16:24, Till Rohrmann <[hidden email]> wrote:
You’re right that the log statements of the LineSplitter are in the logs of the cluster nodes, because that’s where the LineSplitter code is executed. In contrast, you create a TestClass on the client when you submit the program. Therefore, you see the logging statement “Logger in TestClass” on the command line or in the cli log file.

So I would assume that the problem is Yarn’s log aggregation. Either your configuration is not correct or there are still some Yarn containers running after the Flink job has finished. Yarn will only show you the logs after all containers are terminated. Maybe you could check that. Alternatively, you can try to retrieve the taskmanager logs manually by going to the machine where your yarn container was executed. Then under hadoop/logs/userlogs you should find somewhere the logs.

Cheers,
Till
On Fri, Jan 8, 2016 at 3:50 PM, Ana M. Martinez <[hidden email]> wrote:
Thanks for the tip Robert! It was a good idea to rule out other possible causes, but I am afraid that is not the problem. If we stick to the WordCountExample (for simplicity), the Exception is thrown if placed into the flatMap function.
I am going to try to re-write my problem and all the settings below:

When I try to aggregate all logs:
$yarn logs -applicationId application_1452250761414_0005

the following message is retrieved:

16/01/08 13:32:37 INFO client.RMProxy: Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

/var/log/hadoop-yarn/apps/hadoop/logs/application_1452250761414_0005does not exist.

Log aggregation has not completed or is not enabled.

(Tried the same command a few minutes later and got the same message, so might it be that log aggregation is not properly enabled??)

I am going to carefully enumerate all the steps I have followed (and settings) to see if someone can identify why the Logger messages from CORE nodes (in an Amazon cluster) are not shown.

1) Enable yarn.log-aggregation-enable property to true in /etc/alternatives/hadoop-conf/yarn-site.xml.

2) Include log messages in my WordCountExample as follows:
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        
        logger.info("Entering application.");

        DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.writeAsText(“output.txt", FileSystem.WriteMode.OVERWRITE);


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);
        
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
		for (String word : line.split(" ")) {
    			out.collect(new Tuple2<String, Integer>(word, 1));
    			//throw new RuntimeException("LineSplitter class called");
		}
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("TestClass.class");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
3) Start a yarn-cluster and execute my program with the following command:
$./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c eu.amidst.flinklink.examples.WordCountExample ../flinklink.jar

4) The output in the log folder is as follows:

13:31:04,945 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Starting Command Line Client (Version: 0.10.0, Rev:ab2cca4, Date:10.11.2015 @ 13:50:14 UTC)

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Current user: hadoop

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JVM: OpenJDK 64-Bit Server VM - Oracle Corporation - 1.8/25.65-b01

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Maximum heap size: 3344 MiBytes

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JAVA_HOME: /etc/alternatives/jre

13:31:04,950 INFO org.apache.flink.client.CliFrontend - Hadoop version: 2.6.0

13:31:04,950 INFO org.apache.flink.client.CliFrontend - JVM Options:

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog.file=/home/hadoop/flink-0.10.0/log/flink-hadoop-client-ip-172-31-33-221.log

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog4j.configuration=file:/home/hadoop/flink-0.10.0/conf/log4j-cli.properties

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlogback.configurationFile=file:/home/hadoop/flink-0.10.0/conf/logback.xml

13:31:04,951 INFO org.apache.flink.client.CliFrontend - Program Arguments:

13:31:04,951 INFO org.apache.flink.client.CliFrontend - run

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -m

13:31:04,951 INFO org.apache.flink.client.CliFrontend - yarn-cluster

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yn

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ys

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 4

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yjm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ytm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,952 INFO org.apache.flink.client.CliFrontend - -c

13:31:04,952 INFO org.apache.flink.client.CliFrontend - eu.amidst.flinklink.examples.WordCountExample

13:31:04,952 INFO org.apache.flink.client.CliFrontend - ../flinklink.jar

13:31:04,952 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Using configuration directory /home/hadoop/flink-0.10.0/conf

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Trying to load configuration file

13:31:05,193 INFO org.apache.flink.client.CliFrontend - Running 'run' command.

13:31:05,201 INFO org.apache.flink.client.CliFrontend - Building program from JAR file

13:31:05,326 INFO org.apache.flink.client.CliFrontend - YARN cluster mode detected. Switching Log4j output to console

13:31:05,385 INFO org.apache.hadoop.yarn.client.RMProxy - Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

13:31:05,534 INFO org.apache.flink.client.FlinkYarnSessionCli - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.FlinkYarnClient to locate the jar

13:31:05,545 INFO org.apache.flink.yarn.FlinkYarnClient - Using values:

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager count = 1

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - JobManager memory = 1024

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager memory = 1024

13:31:06,112 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/lib/flink-dist-0.10.0.jar to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar

13:31:06,843 INFO org.apache.flink.yarn.Utils - Copying from /home/hadoop/flink-0.10.0/conf/flink-conf.yaml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml

13:31:06,857 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/logback.xml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml

13:31:06,869 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/log4j.properties to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties

13:31:06,892 INFO org.apache.flink.yarn.FlinkYarnClient - Submitting application master application_1452250761414_0005

13:31:06,917 INFO org.apache.hadoop.yarn.client.api.impl.YarnClientImpl - Submitted application application_1452250761414_0005

13:31:06,917 INFO org.apache.flink.yarn.FlinkYarnClient - Waiting for the cluster to be allocated

13:31:06,919 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:07,920 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:08,922 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:09,924 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:10,925 INFO org.apache.flink.yarn.FlinkYarnClient - YARN application has been deployed successfully.

13:31:10,929 INFO org.apache.flink.yarn.FlinkYarnCluster - Start actor system.

13:31:11,412 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:11,472 INFO Remoting - Starting remoting

13:31:11,698 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@172.31.33.221:39464]

13:31:11,733 INFO org.apache.flink.yarn.FlinkYarnCluster - Start application client.

13:31:11,737 INFO org.apache.flink.client.CliFrontend - YARN cluster started

13:31:11,737 INFO org.apache.flink.client.CliFrontend - JobManager web interface address http://ip-172-31-33-221.us-west-2.compute.internal:20888/proxy/application_1452250761414_0005/

13:31:11,737 INFO org.apache.flink.client.CliFrontend - Waiting until all TaskManagers have connected

13:31:11,748 INFO org.apache.flink.yarn.ApplicationClient - Notification about new leader address akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,752 INFO org.apache.flink.client.CliFrontend - No status updates from the YARN cluster received so far. Waiting ...

13:31:11,752 INFO org.apache.flink.yarn.ApplicationClient - Received address of new leader akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,753 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager null.

13:31:11,757 INFO org.apache.flink.yarn.ApplicationClient - Trying to register at JobManager akka.tcp://flink@172.31.45.98:46965/user/jobmanager.

13:31:12,040 INFO org.apache.flink.yarn.ApplicationClient - Successfully registered at the JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782]

13:31:12,253 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:12,753 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,254 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,755 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,255 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,756 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,257 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,758 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:16,258 INFO org.apache.flink.client.CliFrontend - All TaskManagers are connected

13:31:16,264 INFO org.apache.flink.client.program.Client - Starting client actor system

13:31:16,265 INFO org.apache.flink.runtime.client.JobClient - Starting JobClient actor system

13:31:16,283 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:16,288 INFO Remoting - Starting remoting

13:31:16,301 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@127.0.0.1:45919]

13:31:16,302 INFO org.apache.flink.runtime.client.JobClient - Started JobClient actor system at 127.0.0.1:45919

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Using the parallelism provided by the remote cluster (4). To use another parallelism, set it at the ./bin/flink client.

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Starting execution of program

13:31:16,303 INFO org.apache.flink.client.program.Client - Starting program in interactive mode

13:31:16,313 INFO eu.amidst.flinklink.examples.WordCountExample - Entering application.

13:31:16,342 INFO TestClass.class - Logger in TestClass

13:31:16,346 INFO org.apache.flink.api.java.typeutils.TypeExtractor - class eu.amidst.flinklink.examples.WordCountExample$TestClass is not a valid POJO type

13:31:16,376 INFO org.apache.flink.client.CliFrontend - Program execution finished

13:31:16,384 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,386 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,408 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,431 INFO org.apache.flink.client.CliFrontend - Shutting down YARN cluster

13:31:16,431 INFO org.apache.flink.yarn.FlinkYarnCluster - Sending shutdown request to the Application Master

13:31:16,432 INFO org.apache.flink.yarn.ApplicationClient - Sending StopYarnSession request to ApplicationMaster.

13:31:16,568 INFO org.apache.flink.yarn.ApplicationClient - Remote JobManager has been stopped successfully. Stopping local application client

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Stopped Application client.

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782].

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,584 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,595 INFO org.apache.flink.yarn.FlinkYarnCluster - Deleting files in hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005

13:31:16,596 INFO org.apache.flink.yarn.FlinkYarnCluster - Application application_1452250761414_0005 finished with state FINISHED and final state SUCCEEDED at 1452259876445

13:31:16,747 INFO org.apache.flink.yarn.FlinkYarnCluster - YARN Client is shutting down

You can see the log messages from the WordCountExample and TestClass classes. But I have problems to show the logger message (INFO) in the LineSplitter class. Presumably, because it is executed in the CORE nodes and node in the MASTER node (it all runs well in my local computer).

Any tips?

Ana
On 06 Jan 2016, at 15:58, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana

Ana M. Martinez

Re: Problem to show logs in task managers

Hi Till,

Sorry for the delay, you were right, I was not restarting the yarn cluster…

Many thanks for your help!

Ana

On 11 Jan 2016, at 14:39, Till Rohrmann <[hidden email]> wrote:
You have to restart the yarn cluster to let your changes take effect. You can do that via HADOOP_HOME/sbin/stop-yarn.sh; HADOOP_HOME/sbin/start-yarn.sh.

The commands yarn-session.sh ... and bin/flink run -m yarn cluster start a new yarn application within the yarn cluster.

Cheers,
Till
On Mon, Jan 11, 2016 at 1:39 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Thanks for your help. I have checked both in Yarn’s web interface and through command line and it seems that there are not occupied containers.

Additionally, I have checked the configuration values in the web interface and even though I have changed the log.aggregation property in the yarn-site.xml file to true, it appears as false and with the following source label:

<property>

<name>yarn.log-aggregation-enable</name>

<value>false</value>

<source>java.io.BufferedInputStream@3c407114</source>

</property>

I am not sure if that is relevant. I had assumed that the "./bin/flink run -m yarn-cluster" command is starting a yarn session and thus reloading the yarn-site file. Is that right? If I am wrong here, then, how can I restart it so that the modifications in the yarn-site.xml file are considered? (I have also tried with ./bin/yarn-session.sh and then ./bin/flink run without success…).

I am not sure if this is related to flink anymore, should I move my problem to the yarn community instead?

Thanks,

Ana
On 11 Jan 2016, at 10:37, Till Rohrmann <[hidden email]> wrote:
Hi Ana,

good to hear that you found the logging statements. You can check in Yarn’s web interface whether there are still occupied containers. Alternatively you can go to the different machines and run jps which lists you the running Java processes. If you see an ApplicationMaster or YarnTaskManagerRunner process, then there is still a container running with Flink on this machine. I hope this helps you.

Cheers,
Till
On Mon, Jan 11, 2016 at 9:37 AM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Thanks for that! I can see the "Logger in LineSplitter.flatMap” output if I retrieve the task manager logs manually (under /var/log/hadoop-yarn/containers/application_X/…). However that solution is not ideal when for instance I am using 32 machines for my mapReduce operations.

I would like to know why Yarn’s log aggregation is not working. Can you tell me how to check if there are some Yarn containers running after the Flink job has finished? I have tried:

hadoop job -list

but I cannot see any jobs there, although I am not sure that it means that there are not containers running...

Thanks,

Ana
On 08 Jan 2016, at 16:24, Till Rohrmann <[hidden email]> wrote:
You’re right that the log statements of the LineSplitter are in the logs of the cluster nodes, because that’s where the LineSplitter code is executed. In contrast, you create a TestClass on the client when you submit the program. Therefore, you see the logging statement “Logger in TestClass” on the command line or in the cli log file.

So I would assume that the problem is Yarn’s log aggregation. Either your configuration is not correct or there are still some Yarn containers running after the Flink job has finished. Yarn will only show you the logs after all containers are terminated. Maybe you could check that. Alternatively, you can try to retrieve the taskmanager logs manually by going to the machine where your yarn container was executed. Then under hadoop/logs/userlogs you should find somewhere the logs.

Cheers,
Till
On Fri, Jan 8, 2016 at 3:50 PM, Ana M. Martinez <[hidden email]> wrote:
Thanks for the tip Robert! It was a good idea to rule out other possible causes, but I am afraid that is not the problem. If we stick to the WordCountExample (for simplicity), the Exception is thrown if placed into the flatMap function.
I am going to try to re-write my problem and all the settings below:

When I try to aggregate all logs:
$yarn logs -applicationId application_1452250761414_0005

the following message is retrieved:

16/01/08 13:32:37 INFO client.RMProxy: Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

/var/log/hadoop-yarn/apps/hadoop/logs/application_1452250761414_0005does not exist.

Log aggregation has not completed or is not enabled.

(Tried the same command a few minutes later and got the same message, so might it be that log aggregation is not properly enabled??)

I am going to carefully enumerate all the steps I have followed (and settings) to see if someone can identify why the Logger messages from CORE nodes (in an Amazon cluster) are not shown.

1) Enable yarn.log-aggregation-enable property to true in /etc/alternatives/hadoop-conf/yarn-site.xml.

2) Include log messages in my WordCountExample as follows:
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        
        logger.info("Entering application.");

        DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.writeAsText(“output.txt", FileSystem.WriteMode.OVERWRITE);


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);
        
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
		for (String word : line.split(" ")) {
    			out.collect(new Tuple2<String, Integer>(word, 1));
    			//throw new RuntimeException("LineSplitter class called");
		}
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("TestClass.class");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
3) Start a yarn-cluster and execute my program with the following command:
$./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c eu.amidst.flinklink.examples.WordCountExample ../flinklink.jar

4) The output in the log folder is as follows:

13:31:04,945 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Starting Command Line Client (Version: 0.10.0, Rev:ab2cca4, Date:10.11.2015 @ 13:50:14 UTC)

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Current user: hadoop

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JVM: OpenJDK 64-Bit Server VM - Oracle Corporation - 1.8/25.65-b01

13:31:04,947 INFO org.apache.flink.client.CliFrontend - Maximum heap size: 3344 MiBytes

13:31:04,947 INFO org.apache.flink.client.CliFrontend - JAVA_HOME: /etc/alternatives/jre

13:31:04,950 INFO org.apache.flink.client.CliFrontend - Hadoop version: 2.6.0

13:31:04,950 INFO org.apache.flink.client.CliFrontend - JVM Options:

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog.file=/home/hadoop/flink-0.10.0/log/flink-hadoop-client-ip-172-31-33-221.log

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlog4j.configuration=file:/home/hadoop/flink-0.10.0/conf/log4j-cli.properties

13:31:04,950 INFO org.apache.flink.client.CliFrontend - -Dlogback.configurationFile=file:/home/hadoop/flink-0.10.0/conf/logback.xml

13:31:04,951 INFO org.apache.flink.client.CliFrontend - Program Arguments:

13:31:04,951 INFO org.apache.flink.client.CliFrontend - run

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -m

13:31:04,951 INFO org.apache.flink.client.CliFrontend - yarn-cluster

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yn

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ys

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 4

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -yjm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,951 INFO org.apache.flink.client.CliFrontend - -ytm

13:31:04,951 INFO org.apache.flink.client.CliFrontend - 1024

13:31:04,952 INFO org.apache.flink.client.CliFrontend - -c

13:31:04,952 INFO org.apache.flink.client.CliFrontend - eu.amidst.flinklink.examples.WordCountExample

13:31:04,952 INFO org.apache.flink.client.CliFrontend - ../flinklink.jar

13:31:04,952 INFO org.apache.flink.client.CliFrontend - --------------------------------------------------------------------------------

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Using configuration directory /home/hadoop/flink-0.10.0/conf

13:31:04,954 INFO org.apache.flink.client.CliFrontend - Trying to load configuration file

13:31:05,193 INFO org.apache.flink.client.CliFrontend - Running 'run' command.

13:31:05,201 INFO org.apache.flink.client.CliFrontend - Building program from JAR file

13:31:05,326 INFO org.apache.flink.client.CliFrontend - YARN cluster mode detected. Switching Log4j output to console

13:31:05,385 INFO org.apache.hadoop.yarn.client.RMProxy - Connecting to ResourceManager at ip-172-31-33-221.us-west-2.compute.internal/172.31.33.221:8032

13:31:05,534 INFO org.apache.flink.client.FlinkYarnSessionCli - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.FlinkYarnClient to locate the jar

13:31:05,545 INFO org.apache.flink.yarn.FlinkYarnClient - Using values:

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager count = 1

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - JobManager memory = 1024

13:31:05,547 INFO org.apache.flink.yarn.FlinkYarnClient - TaskManager memory = 1024

13:31:06,112 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/lib/flink-dist-0.10.0.jar to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-dist-0.10.0.jar

13:31:06,843 INFO org.apache.flink.yarn.Utils - Copying from /home/hadoop/flink-0.10.0/conf/flink-conf.yaml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/flink-conf.yaml

13:31:06,857 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/logback.xml to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/logback.xml

13:31:06,869 INFO org.apache.flink.yarn.Utils - Copying from file:/home/hadoop/flink-0.10.0/conf/log4j.properties to hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005/log4j.properties

13:31:06,892 INFO org.apache.flink.yarn.FlinkYarnClient - Submitting application master application_1452250761414_0005

13:31:06,917 INFO org.apache.hadoop.yarn.client.api.impl.YarnClientImpl - Submitted application application_1452250761414_0005

13:31:06,917 INFO org.apache.flink.yarn.FlinkYarnClient - Waiting for the cluster to be allocated

13:31:06,919 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:07,920 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:08,922 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:09,924 INFO org.apache.flink.yarn.FlinkYarnClient - Deploying cluster, current state ACCEPTED

13:31:10,925 INFO org.apache.flink.yarn.FlinkYarnClient - YARN application has been deployed successfully.

13:31:10,929 INFO org.apache.flink.yarn.FlinkYarnCluster - Start actor system.

13:31:11,412 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:11,472 INFO Remoting - Starting remoting

13:31:11,698 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@172.31.33.221:39464]

13:31:11,733 INFO org.apache.flink.yarn.FlinkYarnCluster - Start application client.

13:31:11,737 INFO org.apache.flink.client.CliFrontend - YARN cluster started

13:31:11,737 INFO org.apache.flink.client.CliFrontend - JobManager web interface address http://ip-172-31-33-221.us-west-2.compute.internal:20888/proxy/application_1452250761414_0005/

13:31:11,737 INFO org.apache.flink.client.CliFrontend - Waiting until all TaskManagers have connected

13:31:11,748 INFO org.apache.flink.yarn.ApplicationClient - Notification about new leader address akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,752 INFO org.apache.flink.client.CliFrontend - No status updates from the YARN cluster received so far. Waiting ...

13:31:11,752 INFO org.apache.flink.yarn.ApplicationClient - Received address of new leader akka.tcp://flink@172.31.45.98:46965/user/jobmanager with session ID null.

13:31:11,753 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager null.

13:31:11,757 INFO org.apache.flink.yarn.ApplicationClient - Trying to register at JobManager akka.tcp://flink@172.31.45.98:46965/user/jobmanager.

13:31:12,040 INFO org.apache.flink.yarn.ApplicationClient - Successfully registered at the JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782]

13:31:12,253 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:12,753 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,254 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:13,755 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,255 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:14,756 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,257 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:15,758 INFO org.apache.flink.client.CliFrontend - TaskManager status (0/1)

13:31:16,258 INFO org.apache.flink.client.CliFrontend - All TaskManagers are connected

13:31:16,264 INFO org.apache.flink.client.program.Client - Starting client actor system

13:31:16,265 INFO org.apache.flink.runtime.client.JobClient - Starting JobClient actor system

13:31:16,283 INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started

13:31:16,288 INFO Remoting - Starting remoting

13:31:16,301 INFO Remoting - Remoting started; listening on addresses :[akka.tcp://flink@127.0.0.1:45919]

13:31:16,302 INFO org.apache.flink.runtime.client.JobClient - Started JobClient actor system at 127.0.0.1:45919

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Using the parallelism provided by the remote cluster (4). To use another parallelism, set it at the ./bin/flink client.

13:31:16,302 INFO org.apache.flink.client.CliFrontend - Starting execution of program

13:31:16,303 INFO org.apache.flink.client.program.Client - Starting program in interactive mode

13:31:16,313 INFO eu.amidst.flinklink.examples.WordCountExample - Entering application.

13:31:16,342 INFO TestClass.class - Logger in TestClass

13:31:16,346 INFO org.apache.flink.api.java.typeutils.TypeExtractor - class eu.amidst.flinklink.examples.WordCountExample$TestClass is not a valid POJO type

13:31:16,376 INFO org.apache.flink.client.CliFrontend - Program execution finished

13:31:16,384 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,386 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,408 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,431 INFO org.apache.flink.client.CliFrontend - Shutting down YARN cluster

13:31:16,431 INFO org.apache.flink.yarn.FlinkYarnCluster - Sending shutdown request to the Application Master

13:31:16,432 INFO org.apache.flink.yarn.ApplicationClient - Sending StopYarnSession request to ApplicationMaster.

13:31:16,568 INFO org.apache.flink.yarn.ApplicationClient - Remote JobManager has been stopped successfully. Stopping local application client

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Stopped Application client.

13:31:16,570 INFO org.apache.flink.yarn.ApplicationClient - Disconnect from JobManager Actor[akka.tcp://flink@172.31.45.98:46965/user/jobmanager#1549383782].

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Shutting down remote daemon.

13:31:16,573 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remote daemon shut down; proceeding with flushing remote transports.

13:31:16,584 INFO akka.remote.RemoteActorRefProvider$RemotingTerminator - Remoting shut down.

13:31:16,595 INFO org.apache.flink.yarn.FlinkYarnCluster - Deleting files in hdfs://ip-172-31-33-221.us-west-2.compute.internal:8020/user/hadoop/.flink/application_1452250761414_0005

13:31:16,596 INFO org.apache.flink.yarn.FlinkYarnCluster - Application application_1452250761414_0005 finished with state FINISHED and final state SUCCEEDED at 1452259876445

13:31:16,747 INFO org.apache.flink.yarn.FlinkYarnCluster - YARN Client is shutting down

You can see the log messages from the WordCountExample and TestClass classes. But I have problems to show the logger message (INFO) in the LineSplitter class. Presumably, because it is executed in the CORE nodes and node in the MASTER node (it all runs well in my local computer).

Any tips?

Ana
On 06 Jan 2016, at 15:58, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

I am afraid it does not work in any case.

I am following the steps you indicate on your websites (for yarn configuration and loggers with slf4j):
1) Enable log aggregation in yarn-site:
https://ci.apache.org/projects/flink/flink-docs-release-0.7/yarn_setup.html#log-files

2) Include Loggers as indicated here (see WordCountExample below):

https://ci.apache.org/projects/flink/flink-docs-release-0.7/internal_logging.html

But I cannot get the log messages that run in the map functions. Am I missing something?

Thanks,
Ana
On 04 Jan 2016, at 14:00, Till Rohrmann <[hidden email]> wrote:
I think the YARN application has to be finished in order for the logs to be accessible.

Judging from you commands, you’re starting a long running YARN application running Flink with ./bin/yarn-session.sh -n 1 -tm 2048 -s 4. This cluster won’t be used though, because you’re executing your job with ./bin/flink run -m yarn-cluster which will start another YARN application which is only alive as long as the Flink job is executed. If you want to run your job on the long running YARN application, then you simply have to omit -m yarn-cluster.

Cheers,
Till
On Mon, Jan 4, 2016 at 12:36 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a yarn-site.xml).

But the command yarn logs -applicationId application_1451903796996_0008 gives me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx

/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not exist.

Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:

./bin/yarn-session.sh -n 1 -tm 2048 -s 4

and then with a detached screen, run my application with ./bin/flink run -m yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable property well or I am not restarting the Flink JobManager and TaskManagers as I should… Any idea?

Thanks,

Ana
On 18 Dec 2015, at 16:29, Till Rohrmann <[hidden email]> wrote:
In which log file are you exactly looking for the logging statements? And on what machine? You have to look on the machines on which the yarn container were started. Alternatively if you have log aggregation activated, then you can simply retrieve the log files via yarn logs.

Cheers,

Till
On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez <[hidden email]> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple example.

I run the code below with the following command:

./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the flatMap function of the inner LineSplitter class, which is actually the one I am most interested in.

Is that an expected behaviour?

Thanks,

Ana
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}
On 17 Dec 2015, at 16:08, Till Rohrmann <[hidden email]> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging level too high. Could you share the code with us?

Cheers,

Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez <[hidden email]> wrote:

Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are properly shown.

I am also interested in providing my own log4j.properties file. I am using the ./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana