(DEPRECATED) Apache Flink User Mailing List archive.

Re: Starting Flink cluster and running a job

Posted by Ken Krugler on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Jira-issue-Flink-11127-tp26180p26242.html

Hi Boris,

I haven’t seen this exact error, but I have seen similar errors caused by multiple versions of jars on the classpath.

When I’ve run into this particular "XXX is not an instance of YYY" problem, it often seems to be caused by a jar that I should have marked as provided in my pom.

Though I’m typically running on a YARN cluster, not w/K8s, so maybe this doesn’t apply.

— Ken

PS - I assume you’ve been reading https://ci.apache.org/projects/flink/flink-docs-stable/monitoring/debugging_classloading.html

On Feb 19, 2019, at 4:34 PM, Boris Lublinsky <[hidden email]> wrote:
Konstantin,
After experimenting with this for a while, I got to the root cause of the problem
I am running a version of a Taxi ride travel prediction as my sample.
It works fine in Intellij,
But when I am trying to put it in the docker (standard Debian 1.7 image)
It fails with a following error

The program finished with the following exception:

org.apache.flink.client.program.ProgramInvocationException: Job failed. (JobID: 9340e7669e7344ab827fef4ddb5ba73d)
at org.apache.flink.client.program.rest.RestClusterClient.submitJob(RestClusterClient.java:268)
at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:487)
at org.apache.flink.streaming.api.environment.StreamContextEnvironment.execute(StreamContextEnvironment.java:66)
at org.apache.flink.streaming.api.scala.StreamExecutionEnvironment.execute(StreamExecutionEnvironment.scala:654)
at com.lightbend.fdp.sample.flink.app.TravelTimePrediction$.main(TravelTimePrediction.scala:89)
at com.lightbend.fdp.sample.flink.app.TravelTimePrediction.main(TravelTimePrediction.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:529)
at org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:421)
at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:427)
at org.apache.flink.client.cli.CliFrontend.executeProgram(CliFrontend.java:813)
at org.apache.flink.client.cli.CliFrontend.runProgram(CliFrontend.java:287)
at org.apache.flink.client.cli.CliFrontend.run(CliFrontend.java:213)
at org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:1050)
at org.apache.flink.client.cli.CliFrontend.lambda$main$11(CliFrontend.java:1126)
at org.apache.flink.runtime.security.NoOpSecurityContext.runSecured(NoOpSecurityContext.java:30)
at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:1126)
Caused by: org.apache.flink.runtime.client.JobExecutionException: Job execution failed.
at org.apache.flink.runtime.jobmaster.JobResult.toJobExecutionResult(JobResult.java:146)
at org.apache.flink.client.program.rest.RestClusterClient.submitJob(RestClusterClient.java:265)
... 19 more
Caused by: org.apache.kafka.common.KafkaException: Failed to construct kafka producer
at org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:416)
at org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:288)
at org.apache.flink.streaming.connectors.kafka.internal.FlinkKafkaProducer.<init>(FlinkKafkaProducer.java:116)
at org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer011.initProducer(FlinkKafkaProducer011.java:944)
at org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer011.initNonTransactionalProducer(FlinkKafkaProducer011.java:940)
at org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer011.beginTransaction(FlinkKafkaProducer011.java:696)
at org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer011.beginTransaction(FlinkKafkaProducer011.java:94)
at org.apache.flink.streaming.api.functions.sink.TwoPhaseCommitSinkFunction.beginTransactionInternal(TwoPhaseCommitSinkFunction.java:384)
at org.apache.flink.streaming.api.functions.sink.TwoPhaseCommitSinkFunction.initializeState(TwoPhaseCommitSinkFunction.java:375)
at org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer011.initializeState(FlinkKafkaProducer011.java:847)
at org.apache.flink.streaming.util.functions.StreamingFunctionUtils.tryRestoreFunction(StreamingFunctionUtils.java:178)
at org.apache.flink.streaming.util.functions.StreamingFunctionUtils.restoreFunctionState(StreamingFunctionUtils.java:160)
at org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.initializeState(AbstractUdfStreamOperator.java:96)
at org.apache.flink.streaming.api.operators.AbstractStreamOperator.initializeState(AbstractStreamOperator.java:278)
at org.apache.flink.streaming.runtime.tasks.StreamTask.initializeState(StreamTask.java:738)
at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:289)
at org.apache.flink.runtime.taskmanager.Task.run(Task.java:704)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.kafka.common.KafkaException: org.apache.kafka.common.serialization.ByteArraySerializer is not an instance of org.apache.kafka.common.serialization.Serializer
at org.apache.kafka.common.config.AbstractConfig.getConfiguredInstance(AbstractConfig.java:248)
at org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:327)
... 17 more

The closest that I found https://stackoverflow.com/questions/37363119/kafka-producer-org-apache-kafka-common-serialization-stringserializer-could-no
Which talks about class loader. (I tried there solution, but it did not help)
I looked at the loading and I see that the pair of these 2 classes is loaded from my uber jar, but twice.

Have you guys seen this error before?
Any suggestion?
Boris Lublinsky
FDP Architect
[hidden email]
https://www.lightbend.com/
On Feb 19, 2019, at 4:50 AM, Konstantin Knauf <[hidden email]> wrote:
Hi Boris,

without looking at the entrypoint in much detail, generally there should not be a race condition there:

* if the taskmanagers can not connect to the resourcemanager they will retry (per default the timeout is 5 mins)
* if the JobManager does not get enough resources from the ResourceManager it will also wait for the resources/slots to provided. The timeout there is also 5 minutes, I think.

So, this should actually be pretty robust as long as the Taskmanager containers can reach the Jobmanager eventually.

Could you provide the Taskmanager/JobManager logs for such a failure case?

Cheers,

Konstantin
On Mon, Feb 18, 2019 at 1:07 AM Boris Lublinsky <[hidden email]> wrote:
Following https://github.com/apache/flink/tree/release-1.7/flink-container/docker
I have created an entry point, which looks like follows:
#!/bin/sh

################################################################################
#   from https://github.com/apache/flink/blob/release-1.7/flink-container/docker/docker-entrypoint.sh
#   and https://github.com/docker-flink/docker-flink/blob/63b19a904fa8bfd1322f1d59fdb226c82b9186c7/1.7/scala_2.11-alpine/docker-entrypoint.sh
################################################################################

# If unspecified, the hostname of the container is taken as the JobManager address
JOB_MANAGER_RPC_ADDRESS=${JOB_MANAGER_RPC_ADDRESS:-$(hostname -f)}

drop_privs_cmd() {
    if [ $(id -u) != 0 ]; then
        # Don't need to drop privs if EUID != 0
        return
    elif [ -x /sbin/su-exec ]; then
        # Alpine
        echo su-exec flink
    else
        # Others
        echo gosu flink
    fi
}

JOB_MANAGER="jobmanager"
TASK_MANAGER="taskmanager"

CMD="$1"
shift

if [ "${CMD}" = "help" ]; then
    echo "Usage: $(basename $0) (${JOB_MANAGER}|${TASK_MANAGER}|help)"
    exit 0
elif [ "${CMD}" = "${JOB_MANAGER}" -o "${CMD}" = "${TASK_MANAGER}" ]; then
    if [ "${CMD}" = "${TASK_MANAGER}" ]; then
        TASK_MANAGER_NUMBER_OF_TASK_SLOTS=${TASK_MANAGER_NUMBER_OF_TASK_SLOTS:-$(grep -c ^processor /proc/cpuinfo)}

        sed -i -e "s/jobmanager.rpc.address: localhost/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" "$FLINK_HOME/conf/flink-conf.yaml"
        sed -i -e "s/taskmanager.numberOfTaskSlots: 1/taskmanager.numberOfTaskSlots: $TASK_MANAGER_NUMBER_OF_TASK_SLOTS/g" "$FLINK_HOME/conf/flink-conf.yaml"
        echo "blob.server.port: 6124" >> "$FLINK_HOME/conf/flink-conf.yaml"
        echo "query.server.port: 6125" >> "$FLINK_HOME/conf/flink-conf.yaml"

        echo "Starting Task Manager"
        echo "config file: " && grep '^[^\n#]' "$FLINK_HOME/conf/flink-conf.yaml"
        exec $(drop_privs_cmd) "$FLINK_HOME/bin/taskmanager.sh" start-foreground
    else
        sed -i -e "s/jobmanager.rpc.address: localhost/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" "$FLINK_HOME/conf/flink-conf.yaml"
        echo "blob.server.port: 6124" >> "$FLINK_HOME/conf/flink-conf.yaml"
        echo "query.server.port: 6125" >> "$FLINK_HOME/conf/flink-conf.yaml"
        echo "config file: " && grep '^[^\n#]' "$FLINK_HOME/conf/flink-conf.yaml"

        if [ -z "$1" ]; then
           exec $(drop_privs_cmd) "$FLINK_HOME/bin/jobmanager.sh" start-foreground "$@"
        else
            exec $FLINK_HOME/bin/standalone-job.sh start-foreground "$@"
        fi
    fi
fi

exec "$@"
It does work for all the cases, except running standalone job.
The problem, the way I understand it, is a racing condition.
In kubernetes it takes several attempts for establish connection between Job and Task manager, while standalone-job.sh
tries to start a job immediately once the cluster is created (before connection is established).
Is there a better option to implement it starting a job on container startup?
--
Konstantin Knauf | Solutions Architect
+49 160 91394525

--------------------------

Ken Krugler
+1 530-210-6378
http://www.scaleunlimited.com
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