jackrabbit-oak-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Tomek Rękawek (JIRA) <j...@apache.org>
Subject [jira] [Comment Edited] (OAK-4882) Bottleneck in the asynchronous persistent cache
Date Fri, 28 Oct 2016 09:45:58 GMT

    [ https://issues.apache.org/jira/browse/OAK-4882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15614762#comment-15614762
] 

Tomek Rękawek edited comment on OAK-4882 at 10/28/16 9:45 AM:
--------------------------------------------------------------

I committed the async queue simplified as in the discussion above. The commit also includes
heuristics suggest by Chetan.

Trunk: [r1766966|https://svn.apache.org/r1766966], [r1766992|https://svn.apache.org/r1766992].
1.4: [r1766970|https://svna.apche.org/r1766970], [r1766993|https://svn.apache.org/r1766993].


was (Author: tomek.rekawek):
I committed the async queue simplified as in the discussion above. The commit also includes
heuristics suggest by Chetan.

Trunk: [r1766966|https://svn.apache.org/r1766966], [r1766992|https://svn.apache.org/r1766992].
1.4: [r1766970|https://svna.apche.org/r1766970].

> Bottleneck in the asynchronous persistent cache
> -----------------------------------------------
>
>                 Key: OAK-4882
>                 URL: https://issues.apache.org/jira/browse/OAK-4882
>             Project: Jackrabbit Oak
>          Issue Type: Bug
>          Components: cache, documentmk
>    Affects Versions: 1.5.10, 1.4.8
>            Reporter: Tomek Rękawek
>            Assignee: Tomek Rękawek
>             Fix For: 1.6, 1.5.13
>
>         Attachments: OAK-4882.patch
>
>
> The class responsible for accepting new cache operations which will be handled asynchronously
is [CacheActionDispatcher|https://github.com/apache/jackrabbit-oak/blob/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/persistentCache/async/CacheActionDispatcher.java].
In case of a high load, when the queue is full (=1024 entries), the [add()|https://github.com/apache/jackrabbit-oak/blob/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/persistentCache/async/CacheActionDispatcher.java#L86]
method removes the oldest 256 entries. However, we can't afford losing the updates (as it
may result in having stale entries in the cache), so all the removed entries are compacted
into one big invalidate action.
> The compaction action ([CacheActionDispatcher#cleanTheQueue|https://github.com/apache/jackrabbit-oak/blob/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/document/persistentCache/async/CacheActionDispatcher.java#L97])
still holds the lock taken in add() method, so threads which tries to add something to the
queue have to wait until cleanTheQueue() ends.
> Maybe we can optimise the CacheActionDispatcher#add->cleanTheQueue part, so it won't
hold the lock for the whole time.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message