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https://issues.apache.org/jira/browse/HADOOP-13203?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15334359#comment-15334359
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Chris Nauroth commented on HADOOP-13203:
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Steve, thanks for posting the details of the instrumentation.  I think the key 
point there is \{streamOpened=1584\} vs. \{streamOpened=1\}.  If the Spark test 
only triggered 1 streamOpened (without this patch), then it must have been a 
full forward-scan usage pattern.  This matches with my earlier observation 
about {{TestS3AInputStreamPerformance#testReadAheadDefault}}, so for future 
testing, that's a test case we can focus on decoupled from Spark.

> S3a: Consider reducing the number of connection aborts by setting correct 
> length in s3 request
> ----------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-13203
>                 URL: https://issues.apache.org/jira/browse/HADOOP-13203
>             Project: Hadoop Common
>          Issue Type: Sub-task
>          Components: fs/s3
>            Reporter: Rajesh Balamohan
>            Assignee: Rajesh Balamohan
>            Priority: Minor
>         Attachments: HADOOP-13203-branch-2-001.patch, 
> HADOOP-13203-branch-2-002.patch, HADOOP-13203-branch-2-003.patch, 
> HADOOP-13203-branch-2-004.patch, stream_stats.tar.gz
>
>
> Currently file's "contentLength" is set as the "requestedStreamLen", when 
> invoking S3AInputStream::reopen().  As a part of lazySeek(), sometimes the 
> stream had to be closed and reopened. But lots of times the stream was closed 
> with abort() causing the internal http connection to be unusable. This incurs 
> lots of connection establishment cost in some jobs.  It would be good to set 
> the correct value for the stream length to avoid connection aborts. 
> I will post the patch once aws tests passes in my machine.



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