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Hadoop QA commented on HDFS-9198: --------------------------------- \\ \\ | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:red}-1{color} | patch | 0m 0s | The patch command could not apply the patch during dryrun. | \\ \\ || Subsystem || Report/Notes || | Patch URL | http://issues.apache.org/jira/secure/attachment/12766881/HDFS-9198-trunk.patch | | Optional Tests | javadoc javac unit findbugs checkstyle | | git revision | trunk / 8d2d3eb | | Console output | https://builds.apache.org/job/PreCommit-HDFS-Build/13013/console | This message was automatically generated. > Coalesce IBR processing in the NN > --------------------------------- > > Key: HDFS-9198 > URL: https://issues.apache.org/jira/browse/HDFS-9198 > Project: Hadoop HDFS > Issue Type: Improvement > Components: namenode > Affects Versions: 2.0.0-alpha > Reporter: Daryn Sharp > Assignee: Daryn Sharp > Attachments: HDFS-9198-branch2.patch, HDFS-9198-trunk.patch, > HDFS-9198-trunk.patch > > > IBRs from thousands of DNs under load will degrade NN performance due to > excessive write-lock contention from multiple IPC handler threads. The IBR > processing is quick, so the lock contention may be reduced by coalescing > multiple IBRs into a single write-lock transaction. The handlers will also > be freed up faster for other operations. -- This message was sent by Atlassian JIRA (v6.3.4#6332)