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https://issues.apache.org/jira/browse/HADOOP-11684?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14979575#comment-14979575
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Aaron Fabbri commented on HADOOP-11684:
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Thanks for review [~eddyxu]. I will fix the style issues you mention.
On the final point: Using synchronization instead of sleeps to block tasks from
finishing.. I like the idea. I can implement it, but detecting whether or not
the final submit() blocks will still be subject to sleep race condition.
That is, I can guarantee first n threads will not finish before I've determined
that the n+1'th thread has blocked (i.e. latch instead of sleep), but
determining how long to wait until that n+1'th threadPool.submit() has
"blocked" is still a race. I can't distinguish between our thread being
runnable but not scheduled and actually blocking from Java, AFAIK.
Three options:
1. I fix this test (which doesn't run by default) to be less-but-still-racy.
2. I fix all style etc. issues, but leave sleep-based implementation.
3. I remove the unit test. It has served to show the amount of testing done on
the patch, and may be a little too fancy anyways.
> S3a to use thread pool that blocks clients
> ------------------------------------------
>
> Key: HADOOP-11684
> URL: https://issues.apache.org/jira/browse/HADOOP-11684
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: 2.7.0
> Reporter: Thomas Demoor
> Assignee: Thomas Demoor
> Attachments: HADOOP-11684-001.patch, HADOOP-11684-002.patch,
> HADOOP-11684-003.patch, HADOOP-11684-004.patch
>
>
> Currently, if fs.s3a.max.total.tasks are queued and another (part)upload
> wants to start, a RejectedExecutionException is thrown.
> We should use a threadpool that blocks clients, nicely throtthling them,
> rather than throwing an exception. F.i. something similar to
> https://github.com/apache/incubator-s4/blob/master/subprojects/s4-comm/src/main/java/org/apache/s4/comm/staging/BlockingThreadPoolExecutorService.java
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