[jira] [Commented] (FLINK-13493) BoundedBlockingSubpartition only notifies onConsumedSubpartition when all the readers are empty

2019-08-01 Thread zhijiang (JIRA)


[ 
https://issues.apache.org/jira/browse/FLINK-13493?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16897998#comment-16897998
 ] 

zhijiang commented on FLINK-13493:
--

Thanks for the clarification [~azagrebin]!

I agree it should be no problem now because we do not have multiple readers for 
one subpartition concurrently. The current semantic of consuming multiple times 
for one subpartition is only considering the failover case, that means next 
consumption attempt only comes after the previous attempt canceled. The set 
structure of readers in `BoundedBlockingSubpartition` make me think of this 
unnecessary concern.

> BoundedBlockingSubpartition only notifies onConsumedSubpartition when all the 
> readers are empty
> ---
>
> Key: FLINK-13493
> URL: https://issues.apache.org/jira/browse/FLINK-13493
> Project: Flink
>  Issue Type: Improvement
>  Components: Runtime / Network
>Reporter: zhijiang
>Assignee: zhijiang
>Priority: Minor
>
> In previous implementation, it would always notify the {{ResultPartition}} of 
> consumed subpartition if any reader view is released. Based on the 
> reference-counter release strategy it might cause problems if one blocking 
> subpartition has multiple readers. That means the whole result partition 
> might be released but there are still alive readers in some subpartitions.
> Although the default release strategy for blocking partition is based on 
> JM/scheduler notification atm. But if we switch the option to based on 
> consumption notification it would cause problems. And from the subpartition 
> side it should has the right behavior no matter what is the specific release 
> strategy in upper layer.
> In order to fix this bug, the {{BoundedBlockingSubpartition}} would only 
> notify {{onConsumedSubpartition}} when all the readers are empty.



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[jira] [Commented] (FLINK-13493) BoundedBlockingSubpartition only notifies onConsumedSubpartition when all the readers are empty

2019-07-31 Thread Andrey Zagrebin (JIRA)


[ 
https://issues.apache.org/jira/browse/FLINK-13493?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16896834#comment-16896834
 ] 

Andrey Zagrebin commented on FLINK-13493:
-

As I think, we also discussed this with [~StephanEwen]. Now it should not be a 
problem because the existing connection should always end one way or another, 
as we already discussed in FLINK-13478, and the existing readers should be all 
closed, eventually triggering the file deletion. We also switched from counters 
to boolean flags per subpartition to avoid counting of unconsumed subpartitions 
by multiple reader confirmation from other subpartitions. Eventually, we do not 
need the release on consumption for blocking partitions, it stays as a safety 
net at the moment to switch to the previous behaviour. At the moment this issue 
looks like for me the same as concerns described FLINK-13478.

> BoundedBlockingSubpartition only notifies onConsumedSubpartition when all the 
> readers are empty
> ---
>
> Key: FLINK-13493
> URL: https://issues.apache.org/jira/browse/FLINK-13493
> Project: Flink
>  Issue Type: Improvement
>  Components: Runtime / Network
>Reporter: zhijiang
>Assignee: zhijiang
>Priority: Minor
>
> In previous implementation, it would always notify the {{ResultPartition}} of 
> consumed subpartition if any reader view is released. Based on the 
> reference-counter release strategy it might cause problems if one blocking 
> subpartition has multiple readers. That means the whole result partition 
> might be released but there are still alive readers in some subpartitions.
> Although the default release strategy for blocking partition is based on 
> JM/scheduler notification atm. But if we switch the option to based on 
> consumption notification it would cause problems. And from the subpartition 
> side it should has the right behavior no matter what is the specific release 
> strategy in upper layer.
> In order to fix this bug, the {{BoundedBlockingSubpartition}} would only 
> notify {{onConsumedSubpartition}} when all the readers are empty.



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