[ https://issues.apache.org/jira/browse/HDFS-4049?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13476622#comment-13476622 ]
Hudson commented on HDFS-4049: ------------------------------ Integrated in Hadoop-trunk-Commit #2862 (See [https://builds.apache.org/job/Hadoop-trunk-Commit/2862/]) HDFS-4049. Fix hflush performance regression due to nagling delays. Contributed by Todd Lipcon. (Revision 1398591) Result = SUCCESS todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1398591 Files : * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/PacketReceiver.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestMultiThreadedHflush.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/protocol/datatransfer * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/protocol/datatransfer/TestPacketReceiver.java > hflush performance regression due to nagling delays > --------------------------------------------------- > > Key: HDFS-4049 > URL: https://issues.apache.org/jira/browse/HDFS-4049 > Project: Hadoop HDFS > Issue Type: Bug > Components: data-node, performance > Affects Versions: 3.0.0, 2.0.2-alpha > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Priority: Critical > Fix For: 3.0.0, 2.0.3-alpha > > Attachments: hdfs-4049.txt, hdfs-4049.txt, hdfs-4049.txt > > > HDFS-3721 reworked the way that packets are mirrored through the pipeline in > the datanode. This caused two write() calls where there used to be one, which > interacts badly with nagling so that there are 40ms bubbles on hflush() > calls. We didn't notice this in the tests because the hflush perf test only > uses a single datanode. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira