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Daryn Sharp commented on HDFS-8966: ----------------------------------- Would you please elaborate on the design vision for doing the final separation? In my rare spare cycles I've been trying to do the same thing. > 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 > > 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 (v6.3.4#6332)