[jira] [Created] (SPARK-3570) Shuffle write time does not include time to open shuffle files

["Kay Ousterhout (JIRA)" <ji...@apache.org>]

Kay Ousterhout created SPARK-3570:
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             Summary: Shuffle write time does not include time to open shuffle files
                 Key: SPARK-3570
                 URL: https://issues.apache.org/jira/browse/SPARK-3570
             Project: Spark
          Issue Type: Bug
    Affects Versions: 1.1.0, 1.0.2, 0.9.2
            Reporter: Kay Ousterhout
            Assignee: Kay Ousterhout


Currently, the reported shuffle write time does not include time to open the shuffle files.  This time can be very significant when the disk is highly utilized and many shuffle files exist on the machine (I'm not sure how severe this is in 1.0 onward -- since shuffle files are automatically deleted, this may be less of an issue because there are fewer old files sitting around).  In experiments I did, in extreme cases, adding the time to open files can increase the shuffle write time from 5ms (of a 2 second task) to 1 second.  We should fix this for better performance debugging.

Thanks [~shivaram] for helping to diagnose this problem.  cc [~pwendell]



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