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maobaolong commented on HDFS-8966: ---------------------------------- [~hexiaoqiao] [~wheat9] [~jingzhao] Hi~, maybe we can mark some class with threadSafe annotation and guardedby annotation to mark the class, variable and method > Separate the lock used in namespace and block management layer > -------------------------------------------------------------- > > Key: HDFS-8966 > URL: https://issues.apache.org/jira/browse/HDFS-8966 > Project: Hadoop HDFS > Issue Type: Improvement > Reporter: Haohui Mai > Assignee: Haohui Mai > Priority: Major > > Currently the namespace and the block management layer share one giant lock. > One consequence that we have seen more and more often is that the namespace > hangs due to excessive activities from the block management layer. For > example, the NN might take a couple hundred milliseconds to handle a large > block report. Because the NN holds the write lock during processing the block > report, all namespace requests are paused. In production we have seen these > lock contentions cause long latencies and instabilities in the cluster. > This umbrella jira proposes to separate the lock used by namespace and the > block management layer. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org