Re: does flink support yarn/hdfs HA?

Posted by Stephan Ewen on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/does-flink-support-yarn-hdfs-HA-tp16448p16449.html

Hi!

The HDFS config resolution logic is in [1]. It should take the environment variable into account.

The problem (bug) seems to be that in the Yarn Utils, the configuration used for Yarn (AppMaster) loads purely from classpath, not from the environment variables.

And that classpath does not include the proper hdfs-site.xml.

Now, there are two ways I could imagine fixing that:

(1) When instantiating the Yarn Configuration, also add resources from the environment variable as in [1].

(2) The client (which puts together all the resources that should be in the classpath of the processes running on Yarn needs to add hadoop these config files to the resources.

Are the environment variables YARN_CONF_DIR and HADOOP_CONF_DIR typically defined on the nodes of a Yarn cluster?

Stephan

[1]: https://github.com/apache/flink/blob/master/flink-filesystems/flink-hadoop-fs/src/main/java/org/apache/flink/runtime/util/HadoopUtils.java

On Fri, Oct 27, 2017 at 12:38 PM, 邓俊华 <[hidden email]> wrote:

hi,

Now I run spark streming on yarn with yarn/HA. I want to migrate spark streaming to flink. But it can't work. It can't conncet to hdfs logical namenode url.

It always throws exception as fllow. I tried to trace the flink code and I found  there maybe  something wrong when read the hadoop conf.

As fllow, code the failoverProxyProvider is null , so it think  it's a No-HA case. The YarnConfiguration didn't read hdfs-site.xml to get "dfs.client.failover.proxy.provider.startdt" value,only yarn-site.xml and core-site.xml be read.

I have configured and  export YARN_CONF_DIR and HADOOP_CONF_DIR in /etc/profile and I am sure there are *-site.xml in this diretory. I  can  also get the value in env.

Can anybody  provide me some advice? 

 

2017-10-25 21:02:14,721 DEBUG org.apache.hadoop.hdfs.BlockReaderLocal                       - dfs.domain.socket.path = 
2017-10-25 21:02:14,755 ERROR org.apache.flink.yarn.YarnApplicationMasterRunner             - YARN Application Master initialization failed
java.lang.IllegalArgumentException: java.net.UnknownHostException: startdt
        at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:378)
        at org.apache.hadoop.hdfs.NameNodeProxies.createNonHAProxy(NameNodeProxies.java:310)
        at org.apache.hadoop.hdfs.NameNodeProxies.createProxy(NameNodeProxies.java:176)
        at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:678)
        at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:619)
        at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
        at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2669)
        at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)
        at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)
        at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)
        at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
        at org.apache.flink.yarn.Utils.createTaskExecutorContext(Utils.java:385)
        at org.apache.flink.yarn.YarnApplicationMasterRunner.runApplicationMaster(YarnApplicationMasterRunner.java:324)
        at org.apache.flink.yarn.YarnApplicationMasterRunner$1.call(YarnApplicationMasterRunner.java:195)
        at org.apache.flink.yarn.YarnApplicationMasterRunner$1.call(YarnApplicationMasterRunner.java:192)
        at org.apache.flink.runtime.security.HadoopSecurityContext$1.run(HadoopSecurityContext.java:43)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:415)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:<a href="tel:1698" value="+491698" target="_blank">1698)
        at org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:40)
        at org.apache.flink.yarn.YarnApplicationMasterRunner.run(YarnApplicationMasterRunner.java:192)
        at org.apache.flink.yarn.YarnApplicationMasterRunner.main(YarnApplicationMasterRunner.java:116)
Caused by: java.net.UnknownHostException: startdt
        ... 23 more