hadoop-hdfs-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tsz Wo Nicholas Sze (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HDFS-9434) Recommission a datanode with 500k blocks may pause NN for 30 seconds
Date Tue, 17 Nov 2015 00:14:11 GMT
Tsz Wo Nicholas Sze created HDFS-9434:
-----------------------------------------

             Summary: Recommission a datanode with 500k blocks may pause NN for 30 seconds
                 Key: HDFS-9434
                 URL: https://issues.apache.org/jira/browse/HDFS-9434
             Project: Hadoop HDFS
          Issue Type: Improvement
          Components: namenode
            Reporter: Tsz Wo Nicholas Sze
            Assignee: Tsz Wo Nicholas Sze


In BlockManager, processOverReplicatedBlocksOnReCommission is called within the namespace
lock.  There is a (not very useful) log message printed in processOverReplicatedBlock.  When
there is a large number of blocks stored in a storage, printing the log message for each block
can pause NN to process any other operations.  We did see that it could pause NN  for 30 seconds
for a storage with 500k blocks.

I suggest to change the log message to trace level as a quick fix.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message