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Steve Loughran commented on HADOOP-15209: ----------------------------------------- Patch 005. * improve copycommitter logging * contains the checksum bypassing of HADOOP-15273, including not asking for a checksum on the destFS if the srcFS doesn't have one. That way, if you are doing a distcp from localfs or some store FS without checksums (wasb,...) then it will avoid the HTTP/RPC call for the dest FS.Makes a big difference from localfs to s3 > DistCp to eliminate needless deletion of files under already-deleted > directories > -------------------------------------------------------------------------------- > > Key: HADOOP-15209 > URL: https://issues.apache.org/jira/browse/HADOOP-15209 > Project: Hadoop Common > Issue Type: Improvement > Components: tools/distcp > Affects Versions: 2.9.0 > Reporter: Steve Loughran > Assignee: Steve Loughran > Priority: Major > Attachments: HADOOP-15209-001.patch, HADOOP-15209-002.patch, > HADOOP-15209-003.patch, HADOOP-15209-004.patch, HADOOP-15209-005.patch > > > DistCP issues a delete(file) request even if is underneath an already deleted > directory. This generates needless load on filesystems/object stores, and, if > the store throttles delete, can dramatically slow down the delete operation. > If the distcp delete operation can build a history of deleted directories, > then it will know when it does not need to issue those deletes. > Care is needed here to make sure that whatever structure is created does not > overload the heap of the process. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org