[ 
https://issues.apache.org/jira/browse/HDFS-8920?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14746906#comment-14746906
 ] 

Rui Li commented on HDFS-8920:
------------------------------

I tried several failures locally and cannot reproduce them. Also both 
{{TestDFSInputStream}} and {{TestDFSStripedInputStream}} pass on my side. So I 
suppose the failures here are not related.

Since the patch only changes how we print logs, I didn't add new tests for it. 
I did manually perform some tests on a cluster, as I mentioned above.

> Erasure Coding: when recovering lost blocks, logs can be too verbose and hurt 
> performance
> -----------------------------------------------------------------------------------------
>
>                 Key: HDFS-8920
>                 URL: https://issues.apache.org/jira/browse/HDFS-8920
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>            Reporter: Rui Li
>            Assignee: Rui Li
>         Attachments: HDFS-8920-HDFS-7285.1.patch
>
>
> When we test reading data with datanodes killed, 
> {{DFSInputStream::getBestNodeDNAddrPair}} becomes a hot spot method and 
> effectively blocks the client JVM. This log seems too verbose:
> {code}
>     if (chosenNode == null) {
>       DFSClient.LOG.warn("No live nodes contain block " + block.getBlock() +
>           " after checking nodes = " + Arrays.toString(nodes) +
>           ", ignoredNodes = " + ignoredNodes);
>       return null;
>     }
> {code}



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

Reply via email to