Haohui Mai created HDFS-8966:
--------------------------------
Summary: 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)
