[
https://issues.apache.org/jira/browse/TEZ-4080?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16926742#comment-16926742
]
Zoltan Haindrich commented on TEZ-4080:
---------------------------------------
Thank you [~jeagles] for taking a look!
sorry; but I was busy doing other things - always wanted to get back to this;
now it seems I can get back to this....
I've tried to use this cloaseAllForUGI methods and the robustness test I've put
together pass with these changes as well...
Somehow I don't feel that using those methods will lead to 100% correct
solutions in every cases - In Hive we may have multiple sessions - even for the
same user; if I understand this correctly - issuing a closeall for one session
will kill the filesystem objects for the other as well....anyway... I will
create some testcases for that - and see how wrong I am with the these
assumptions :D
> TezClient should close FileSystem objects to prevent leak
> ---------------------------------------------------------
>
> Key: TEZ-4080
> URL: https://issues.apache.org/jira/browse/TEZ-4080
> Project: Apache Tez
> Issue Type: Bug
> Affects Versions: 0.9.1
> Reporter: Zoltan Haindrich
> Priority: Major
> Attachments: TEZ-4080.branch-0.9.1.02.patch,
> TEZ-4080.branch-0.9.1.patch
>
>
> When opening/closing a lot of tez clients; some FileSystem object references
> are retained even after the client is closed - due to the fact the
> FileSystem has a "cache" which collects all open FileSystem objects - to be
> able to close all of them from a single shutdownhook.
> Not closing these FileSystem objects causes them to pile up in the "cache"
> which has hard references to them
> In a simple hive test which was run with 150M of memory; these "lost"
> filesystem objects could result in an OOM after ~170 sessions.
> A sample creation stack trace of a FileSystem object:
> {code}
> at
> org.apache.hadoop.hive.ql.io.ProxyLocalFileSystem.<init>(ProxyLocalFileSystem.java:49)
> at sun.reflect.GeneratedConstructorAccessor83.newInstance(Unknown
> Source)
> at
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
> at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
> at
> org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:133)
> at
> org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3353)
> at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:124)
> at
> org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:3403)
> at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:3371)
> at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:477)
> at org.apache.hadoop.fs.Path.getFileSystem(Path.java:361)
> at
> org.apache.tez.dag.app.DAGAppMaster.serviceInit(DAGAppMaster.java:502)
> at
> org.apache.hadoop.service.AbstractService.init(AbstractService.java:164)
> at org.apache.tez.dag.app.DAGAppMaster$9.run(DAGAppMaster.java:2663)
> {code}
--
This message was sent by Atlassian Jira
(v8.3.2#803003)
