flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Zhenzhong Xu (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (FLINK-4660) HadoopFileSystem (with S3A) may leak connections, which cause job to stuck in a restarting loop
Date Wed, 21 Sep 2016 19:49:20 GMT

     [ https://issues.apache.org/jira/browse/FLINK-4660?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Zhenzhong Xu updated FLINK-4660:
    Attachment: Screen Shot 2016-09-20 at 2.49.32 PM.png
                Screen Shot 2016-09-20 at 2.49.14 PM.png

> HadoopFileSystem (with S3A) may leak connections, which cause job to stuck in a restarting
> -----------------------------------------------------------------------------------------------
>                 Key: FLINK-4660
>                 URL: https://issues.apache.org/jira/browse/FLINK-4660
>             Project: Flink
>          Issue Type: Bug
>          Components: State Backends, Checkpointing
>            Reporter: Zhenzhong Xu
>            Priority: Critical
>         Attachments: Screen Shot 2016-09-20 at 2.49.14 PM.png, Screen Shot 2016-09-20
at 2.49.32 PM.png
> Flink job with checkpoints enabled and configured to use S3A file system backend, sometimes
experiences checkpointing failure due to S3 consistency issue. This behavior is also reported
by other people and documented in https://issues.apache.org/jira/browse/FLINK-4218.
> This problem gets magnified by current HadoopFileSystem implementation, which can potentially
leak S3 client connections, and eventually get into a restarting loop with “Timeout waiting
for a connection from pool” exception thrown from aws client.
> I looked at the code, seems HadoopFileSystem.java never invoke close() method on fs object
upon failure, but the FileSystem may be re-initialized every time the job gets restarted.
> A few evidence I observed:
> 1. When I set the connection pool limit to 128, and below commands shows 128 connections
are stuck in CLOSE_WAIT state.
> 2. task manager logs indicates that state backend file system consistently getting initialized
upon job restarting.
> 3. Log indicates there is NPE during cleanning up of stream task which was caused by
“Timeout waiting for connection from pool” exception when trying to create a directory
in S3 bucket.
> 2016-09-02 08:17:50,886 ERROR org.apache.flink.streaming.runtime.tasks.StreamTask - Error
during cleanup of stream task
> java.lang.NullPointerException
> at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.cleanup(OneInputStreamTask.java:73)
> at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:323)
> at org.apache.flink.runtime.taskmanager.Task.run(Task.java:589)
> at java.lang.Thread.run(Thread.java:745)
> 4.It appears StreamTask from invoking checkpointing operation, to handling failure, there
is no logic associated with closing Hadoop File System object (which internally includes S3
aws client object), which resides in HadoopFileSystem.java.

This message was sent by Atlassian JIRA

View raw message