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https://issues.apache.org/jira/browse/FLINK-9061?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16417032#comment-16417032
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Stephan Ewen commented on FLINK-9061:
-------------------------------------
One advantage of making the changes in the state backend would be that you can
add entropy to the state files written by the TaskManager, but leave the
metadata file path as is (easier to find when trying to resume manually from a
savepoint or externalized checkpoint).
You can also try as a temporary workaround the connection limiting feature of
the Flink FileSystems:
https://ci.apache.org/projects/flink/flink-docs-release-1.4/ops/filesystems.html#connection-limiting
> S3 checkpoint data not partitioned well -- causes errors and poor performance
> -----------------------------------------------------------------------------
>
> Key: FLINK-9061
> URL: https://issues.apache.org/jira/browse/FLINK-9061
> Project: Flink
> Issue Type: Bug
> Components: FileSystem, State Backends, Checkpointing
> Affects Versions: 1.4.2
> Reporter: Jamie Grier
> Priority: Critical
>
> I think we need to modify the way we write checkpoints to S3 for high-scale
> jobs (those with many total tasks). The issue is that we are writing all the
> checkpoint data under a common key prefix. This is the worst case scenario
> for S3 performance since the key is used as a partition key.
>
> In the worst case checkpoints fail with a 500 status code coming back from S3
> and an internal error type of TooBusyException.
>
> One possible solution would be to add a hook in the Flink filesystem code
> that allows me to "rewrite" paths. For example say I have the checkpoint
> directory set to:
>
> s3://bucket/flink/checkpoints
>
> I would hook that and rewrite that path to:
>
> s3://bucket/[HASH]/flink/checkpoints, where HASH is the hash of the original
> path
>
> This would distribute the checkpoint write load around the S3 cluster evenly.
>
> For reference:
> https://aws.amazon.com/premiumsupport/knowledge-center/s3-bucket-performance-improve/
>
> Any other people hit this issue? Any other ideas for solutions? This is a
> pretty serious problem for people trying to checkpoint to S3.
>
> -Jamie
>
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