[FLINK-9061] Add entropy to s3 path for better scalability

• Type: Improvement
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.4.2, 1.5.0
• Fix Version/s: 1.6.2, 1.7.0
• Component/s: FileSystems, Runtime / State Backends
• Labels: pull-request-available
• Assignee: Indrajit Roychoudhury
• Reporter: Jamie Grier
• Created: 22/Mar/18 22:49
• Updated: 02/Oct/19 17:44
• Resolved: 17/Oct/18 08:49

Description

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
 

Issue Links

• is related to: HADOOP-15347 S3ARetryPolicy to handle AWS 500 responses/error code TooBusyException with the throttle backoff policy
• links to: GitHub Pull Request #6302
• links to: GitHub Pull Request #6302
• links to: GitHub Pull Request #6604
• links to: GitHub Pull Request #6726