[
https://issues.apache.org/jira/browse/HDFS-1110?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12866060#action_12866060
]
dhruba borthakur commented on HDFS-1110:
----------------------------------------
Awesome. I like this idea because it has no configuration shing-bang and is
automatic. My opinion is that it is ok to do this only during NN startup time.
Maybe you can have only one dictionary where you store the count-of-occurances
as well. i.e move the count from the transient map to the dictionary...
otherwise the same logic as u described. when the image is fully loaded, we
have to purge the dictionary of all items whose count is lesser than 10 .
also, this has some relationship to HDFS-1140.
> 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.
