[
https://issues.apache.org/jira/browse/IGNITE-4426?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15748053#comment-15748053
]
ASF GitHub Bot commented on IGNITE-4426:
----------------------------------------
GitHub user devozerov opened a pull request:
https://github.com/apache/ignite/pull/1344
IGNITE-4426
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/gridgain/apache-ignite ignite-4426
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/ignite/pull/1344.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #1344
----
commit df99bd4bba938862f2a942d1f470dcfbb9090bdd
Author: devozerov <[email protected]>
Date: 2016-12-14T11:13:16Z
Implemented.
----
> Hadoop: allow optional classloader reuse between tasks.
> -------------------------------------------------------
>
> Key: IGNITE-4426
> URL: https://issues.apache.org/jira/browse/IGNITE-4426
> Project: Ignite
> Issue Type: Sub-task
> Components: hadoop
> Affects Versions: 1.8
> Reporter: Vladimir Ozerov
> Assignee: Vladimir Ozerov
> Fix For: 2.0
>
>
> *Problem*
> Currently we create separate {{HadoopClassLoader}} for each and every MR
> task. It has serious performance implications:
> 1) Every task have to reload classes form disk;
> 2) Every task starts from "cold" state with not-compiled classes;
> 3) Very high permgen/metaspace and code cache regions usage.
> We can observe, that every task classloader works with the same JARs. It
> means that the only case when we really need to isolate tasks through
> classloaders is when they depend on some static data, which should not be
> shared.
> *Proposal*
> - Share {{HadoopClassLoader}} between tasks by default;
> - Allow to optionally disable this opto.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
