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stack commented on HDFS-6109: ----------------------------- Patch lgtm (I liked the [~cmccabe] suggestion that we keep FsDatasetImpl encapsulated). > let sync_file_range() system call run in background > --------------------------------------------------- > > Key: HDFS-6109 > URL: https://issues.apache.org/jira/browse/HDFS-6109 > Project: Hadoop HDFS > Issue Type: Improvement > Components: datanode > Affects Versions: 3.0.0, 2.3.0 > Reporter: Liang Xie > Assignee: Liang Xie > Attachments: HDFS-6109-v2.txt, HDFS-6109-v3.txt, HDFS-6109-v4.txt, > HDFS-6109.txt > > > Through we passed SYNC_FILE_RANGE_WRITE to sync_file_range, to make it as > asynchronous as possible, it still could be blocked, e.g. the os io request > queue is full. > Since we use sync_file_range just as a page cache advisor role:) it doesn't > decide or guarantee the real durability, it would be nice if we could run it > in backgroud. At least my test log showed, a few sync_file_range calls still > cost tens of ms or more, due to the happened location is in the critical > write path(BlockReceiver class), from a upper view, like HBase application, > will "hung" tens of ms as well during Hlog syncing. > Generally speaking, the patch could not improve too much, but, better than > before, right ? :) -- This message was sent by Atlassian JIRA (v6.2#6252)