[jira] [Commented] (FLINK-4218) Sporadic "java.lang.RuntimeException: Error triggering a checkpoint..." causes task restarting

["Stephan Ewen (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-4218?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15513234#comment-15513234 ] 

Stephan Ewen commented on FLINK-4218:
-------------------------------------

[~zhenzhongxu] Adding you to this conversation.

My assumptions is that the problem is as follows: The file exists and is consistently visible (if I understand S3 correctly), but the parent directory's metadata is eventual consistent. The operation that fails here is the lookup of the file size, which is in most file systems an operation on the parent directory, not the file itself. So that would explain why it occasionally fails.

What is the best way to fix this? Simply have a few retries? If it still fails after the retries, simply use a special value for unknown file size?
The state size information is used mainly for informational purposes, like in the web UI and in metrics.

> Sporadic "java.lang.RuntimeException: Error triggering a checkpoint..." causes task restarting
> ----------------------------------------------------------------------------------------------
>
>                 Key: FLINK-4218
>                 URL: https://issues.apache.org/jira/browse/FLINK-4218
>             Project: Flink
>          Issue Type: Improvement
>    Affects Versions: 1.1.0
>            Reporter: Sergii Koshel
>
> Sporadically see exception as below. And restart of task because of it.
> {code:title=Exception|borderStyle=solid}
> java.lang.RuntimeException: Error triggering a checkpoint as the result of receiving checkpoint barrier
> 	at org.apache.flink.streaming.runtime.tasks.StreamTask$3.onEvent(StreamTask.java:785)
> 	at org.apache.flink.streaming.runtime.tasks.StreamTask$3.onEvent(StreamTask.java:775)
> 	at org.apache.flink.streaming.runtime.io.BarrierBuffer.processBarrier(BarrierBuffer.java:203)
> 	at org.apache.flink.streaming.runtime.io.BarrierBuffer.getNextNonBlocked(BarrierBuffer.java:129)
> 	at org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:183)
> 	at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:66)
> 	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:265)
> 	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:588)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.io.FileNotFoundException: No such file or directory: s3://<bucket_name_here>/flink/checkpoints/ece317c26960464ba5de75f3bbc38cb2/chk-8810/96eebbeb-de14-45c7-8ebb-e7cde978d6d3
> 	at org.apache.hadoop.fs.s3a.S3AFileSystem.getFileStatus(S3AFileSystem.java:996)
> 	at org.apache.hadoop.fs.s3a.S3AFileSystem.getFileStatus(S3AFileSystem.java:77)
> 	at org.apache.flink.runtime.fs.hdfs.HadoopFileSystem.getFileStatus(HadoopFileSystem.java:351)
> 	at org.apache.flink.runtime.state.filesystem.AbstractFileStateHandle.getFileSize(AbstractFileStateHandle.java:93)
> 	at org.apache.flink.runtime.state.filesystem.FileStreamStateHandle.getStateSize(FileStreamStateHandle.java:58)
> 	at org.apache.flink.runtime.state.AbstractStateBackend$DataInputViewHandle.getStateSize(AbstractStateBackend.java:482)
> 	at org.apache.flink.streaming.runtime.tasks.StreamTaskStateList.getStateSize(StreamTaskStateList.java:77)
> 	at org.apache.flink.streaming.runtime.tasks.StreamTask.performCheckpoint(StreamTask.java:604)
> 	at org.apache.flink.streaming.runtime.tasks.StreamTask$3.onEvent(StreamTask.java:779)
> 	... 8 more
> {code}
> File actually exists on S3. 
> I suppose it is related to some race conditions with S3 but would be good to retry a few times before stop task execution.



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