[ 
https://issues.apache.org/jira/browse/HDFS-11661?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15974701#comment-15974701
 ] 

Wei-Chiu Chuang commented on HDFS-11661:
----------------------------------------

I am +1 for reverting HDFS-10797. In fact, that's what I initially wanted to do 
when filing HDFS-11515 (also broken by HDFS-10797).

> GetContentSummary uses excessive amounts of memory
> --------------------------------------------------
>
>                 Key: HDFS-11661
>                 URL: https://issues.apache.org/jira/browse/HDFS-11661
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: namenode
>    Affects Versions: 2.8.0, 3.0.0-alpha2
>            Reporter: Nathan Roberts
>            Priority: Blocker
>         Attachments: Heap growth.png
>
>
> ContentSummaryComputationContext::nodeIncluded() is being used to keep track 
> of all INodes visited during the current content summary calculation. This 
> can be all of the INodes in the filesystem, making for a VERY large hash 
> table. This simply won't work on large filesystems. 
> We noticed this after upgrading a namenode with ~100Million filesystem 
> objects was spending significantly more time in GC. Fortunately this system 
> had some memory breathing room, other clusters we have will not run with this 
> additional demand on memory.
> This was added as part of HDFS-10797 as a way of keeping track of INodes that 
> have already been accounted for - to avoid double counting.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to