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He Liangliang updated HDFS-9422: -------------------------------- Description: In DirectoryScanner, the scan call hold the global dataset lock for quite long time (typically max value > 5 secs for 500k blocks). This will stuck the client which need acquire this lock. For applications like HBase, this will affect the latency. In fact, this lock is unnecessary. (was: In DirectoryScanner, the scan call hold the global dataset lock for quite long time (typically > 5 secs for 500k blocks). This will stuck the client which need acquire this lock. For applications like HBase, this will affect the latency. In fact, this lock is unnecessary.) > Unnecessary FsDatasetImpl locking in DirectoryScanner cause periodic datanode > pauses > ------------------------------------------------------------------------------------ > > Key: HDFS-9422 > URL: https://issues.apache.org/jira/browse/HDFS-9422 > Project: Hadoop HDFS > Issue Type: Bug > Reporter: He Liangliang > Assignee: He Liangliang > Attachments: HDFS-9422.patch > > > In DirectoryScanner, the scan call hold the global dataset lock for quite > long time (typically max value > 5 secs for 500k blocks). This will stuck the > client which need acquire this lock. For applications like HBase, this will > affect the latency. In fact, this lock is unnecessary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)