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Lars Hofhansl commented on HDFS-744: ------------------------------------ I like SequenceFile.Writer implementing Syncable. I see the argument for just a single flag. Yes, that would simpler. Just have a sync-flag, the client decides when to send it (either upon calling hsync, or with the last packet in the block if the stream was created with SYNC_BLOCK). > Support hsync in HDFS > --------------------- > > Key: HDFS-744 > URL: https://issues.apache.org/jira/browse/HDFS-744 > Project: Hadoop HDFS > Issue Type: New Feature > Components: data-node, hdfs client > Reporter: Hairong Kuang > Assignee: Lars Hofhansl > Attachments: HDFS-744-trunk-v2.patch, HDFS-744-trunk-v3.patch, > HDFS-744-trunk-v4.patch, HDFS-744-trunk-v5.patch, HDFS-744-trunk.patch, > hdfs-744-v2.txt, hdfs-744-v3.txt, hdfs-744.txt > > > HDFS-731 implements hsync by default as hflush. As descriibed in HADOOP-6313, > the real expected semantics should be "flushes out to all replicas and all > replicas have done posix fsync equivalent - ie the OS has flushed it to the > disk device (but the disk may have it in its cache)." This jira aims to > implement the expected behaviour. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira