[
https://issues.apache.org/jira/browse/HDFS-1110?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12865661#action_12865661
]
Suresh Srinivas commented on HDFS-1110:
---------------------------------------
470MB was based on my rough calculation. Look at detailed info I posted
earlier. If we use dictionary for names used more than 10, the savings is 1.6G
in old generation of size 37G (BTW not all the 37G was used in old gen, ~30G
was used and the remaining was headroom).
> Namenode heap optimization - reuse objects for commonly used file names
> -----------------------------------------------------------------------
>
> Key: HDFS-1110
> URL: https://issues.apache.org/jira/browse/HDFS-1110
> Project: Hadoop HDFS
> Issue Type: Improvement
> Reporter: Suresh Srinivas
> Assignee: Suresh Srinivas
> Fix For: 0.22.0
>
> Attachments: hdfs-1110.2.patch, hdfs-1110.patch
>
>
> There are a lot of common file names used in HDFS, mainly created by
> mapreduce, such as file names starting with "part". Reusing byte[]
> corresponding to these recurring file names will save significant heap space
> used for storing the file names in millions of INodeFile objects.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
