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Apache Spark commented on SPARK-3570: ------------------------------------- User 'kayousterhout' has created a pull request for this issue: https://github.com/apache/spark/pull/4550 > 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 > Components: Spark Core > Affects Versions: 0.9.2, 1.0.2, 1.1.0 > Reporter: Kay Ousterhout > Assignee: Kay Ousterhout > Attachments: 3a_1410854905_0_job_log_waterfall.pdf, > 3a_1410957857_0_job_log_waterfall.pdf > > > 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] -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org