[
https://issues.apache.org/jira/browse/HDFS-12288?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17114886#comment-17114886
]
Íñigo Goiri commented on HDFS-12288:
------------------------------------
I think we left enough time for people to speak up.
I'll go ahead and commit it.
> Fix DataNode's xceiver count calculation
> ----------------------------------------
>
> Key: HDFS-12288
> URL: https://issues.apache.org/jira/browse/HDFS-12288
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: datanode, hdfs
> Reporter: Lukas Majercak
> Assignee: Lisheng Sun
> Priority: Major
> Attachments: HDFS-12288.001.patch, HDFS-12288.002.patch,
> HDFS-12288.003.patch, HDFS-12288.004.patch, HDFS-12288.005.patch,
> HDFS-12288.006.patch, HDFS-12288.007.patch, HDFS-12288.008.patch
>
>
> The problem with the ThreadGroup.activeCount() method is that the method is
> only a very rough estimate, and in reality returns the total number of
> threads in the thread group as opposed to the threads actually running.
> In some DNs, we saw this to return 50~ for a long time, even though the
> actual number of DataXceiver threads was next to none.
> This is a big issue as we use the xceiverCount to make decisions on the NN
> for choosing replication source DN or returning DNs to clients for R/W.
> The plan is to reuse the DataNodeMetrics.dataNodeActiveXceiversCount value
> which only accounts for actual number of DataXcevier threads currently
> running and thus represents the load on the DN much better.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
