[ 
https://issues.apache.org/jira/browse/HDFS-14728?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16906852#comment-16906852
 ] 

xuzq edited comment on HDFS-14728 at 8/14/19 4:14 AM:
------------------------------------------------------

Thanks [~elgoiri] for the comment. And I attach [^HDFS-14728-trunk-003.patch], 
please review.
{quote}By the way, we should cover what this exception is and have tests if so.
{quote}
It may be throw IOException, RunTimeException and Error.

And I'm sorry I don't know which cases in the current code may cause 
RunTimeException and Errors.:(


was (Author: xuzq_zander):
Thanks [~elgoiri] for the comment. And I attach [^HDFS-14728-trunk-002.patch], 
please review.
{quote} By the way, we should cover what this exception is and have tests if so.
{quote}
It may be throw IOException, RunTimeException and Error.

And I'm sorry I don't know which cases in the current code may cause 
RunTimeException and Errors.:(

> RBF: GetDatanodeReport causes a large GC pressure on the NameNodes
> ------------------------------------------------------------------
>
>                 Key: HDFS-14728
>                 URL: https://issues.apache.org/jira/browse/HDFS-14728
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: rbf
>            Reporter: xuzq
>            Assignee: xuzq
>            Priority: Major
>         Attachments: HDFS-14728-trunk-001.patch, HDFS-14728-trunk-002.patch, 
> HDFS-14728-trunk-003.patch
>
>
> When a cluster contains millions of DNs, *GetDatanodeReport* is pretty 
> expensive, and it will cause a large GC pressure on NameNode.
> When multiple NSs share the millions DNs by federation and the router listens 
> to the NSs, the problem will be more serious.
> All the NSs will be GC at the same time.
> RBF should cache the datanode report informations and have an option to 
> disable the cache.



--
This message was sent by Atlassian JIRA
(v7.6.14#76016)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org

Reply via email to