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From "Raghu Angadi (JIRA)" <j...@apache.org>
Subject [jira] Updated: (HADOOP-3381) INode interlinks can multiply effect memory leaks
Date Tue, 13 May 2008 18:31:55 GMT

     [ https://issues.apache.org/jira/browse/HADOOP-3381?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Raghu Angadi updated HADOOP-3381:
---------------------------------

    Description: 
Say a directory 'DIR' has a directory tree under it with 10000 files and directories. Each
INode keeps refs to parent and children. When DIR is deleted, memory wise we essentially delete
link from its parent (and delete the all the blocks from {{blocksMap}}). We don't modify its
children. This is ok since this will form an island of references and will be gc-ed. Thats
when everything is perfect. But if there is a bug that leaves a ref from a valid object (there
is a suspect, I will another jira) to even one of these 10000 files, it could hold up all
the INode and related objects. This can make a smaller mem leak many times more severe.




  was:

Say a directory 'DIR' has a directory tree under it with say 10000 files and directories.
Each INode keeps refs to parent and children. When DIR is deleted, memory wise we essentially
delete link from its parent (and delete the corresponding blocks from {{blocksMap}}). We don't
modify its children. This is ok since this will form an island of references and will be gc-ed.
Thats when everything is perfect. But if there is a bug that leaves a ref from a valid object
(there is a suspect, I will another jira) to even one of these 10000 files, it could hold
up all the INode and related objects. This can make a smaller mem leak many times more severe.





> INode interlinks can multiply effect memory leaks
> -------------------------------------------------
>
>                 Key: HADOOP-3381
>                 URL: https://issues.apache.org/jira/browse/HADOOP-3381
>             Project: Hadoop Core
>          Issue Type: Bug
>    Affects Versions: 0.16.0
>            Reporter: Raghu Angadi
>            Assignee: Raghu Angadi
>
> Say a directory 'DIR' has a directory tree under it with 10000 files and directories.
Each INode keeps refs to parent and children. When DIR is deleted, memory wise we essentially
delete link from its parent (and delete the all the blocks from {{blocksMap}}). We don't modify
its children. This is ok since this will form an island of references and will be gc-ed. Thats
when everything is perfect. But if there is a bug that leaves a ref from a valid object (there
is a suspect, I will another jira) to even one of these 10000 files, it could hold up all
the INode and related objects. This can make a smaller mem leak many times more severe.

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