[ 
https://issues.apache.org/jira/browse/HDFS-9434?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15025532#comment-15025532
 ] 

Hudson commented on HDFS-9434:
------------------------------

FAILURE: Integrated in Hadoop-Mapreduce-trunk-Java8 #717 (See 
[https://builds.apache.org/job/Hadoop-Mapreduce-trunk-Java8/717/])
Move HDFS-9434 to 2.6.3 in CHANGES.txt. (szetszwo: rev 
56493cda04e30ab737fc6cecc8c43a87d5b006b7)
* hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt


> 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
>             Fix For: 2.6.3
>
>         Attachments: h9434_20151116.patch
>
>
> 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)

Reply via email to