[
https://issues.apache.org/jira/browse/HBASE-5088?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13175887#comment-13175887
]
Jieshan Bean commented on HBASE-5088:
-------------------------------------
@Ted,
At first, I also thought we would get a higher performance with this patch,
because all the keywords of "synchronized" removed. But it slowdown.
I agree with the explaination from Lars.
Our JDK version is 1.6.0_22. And the below is our OS information:
{noformat}
C3S3:~ # cat /proc/version
Linux version 2.6.32.12-0.7-default (geeko@buildhost) (gcc version 4.3.4
[gcc-4_ 3-branch revision 152973]
(SUSE Linux) ) #1 SMP 2010-05-20 11:14:20 +0200
C3S3:/proc # lsb_release -a
LSB Version:
core-2.0-noarch:core-3.2-noarch:core-4.0-noarch:core-2.0-x86_64:core-3.2-x86_64:core-4.0-x86_64:desktop-4.0-amd64:desktop-4.0-noarch:graphics-2.0-amd64:graphics-2.0-noarch:graphics-3.2-amd64:graphics-3.2-noarch:graphics-4.0-amd64:graphics-4.0-noarch
Distributor ID: SUSE LINUX
Description: SUSE Linux Enterprise Server 11 (x86_64)
Release: 11
Codename: n/a
{noformat}
We'll take more tests accross the read vs write and give out the results.
@Lars,
Sorry, I didn't do another comparison with SoftvalueSortedMap replaced by
ConcurrentSkiplistMap.And am planning to do it. Including the functional test
and the performance test. And then, we can choose a better one.
> A concurrency issue on SoftValueSortedMap
> -----------------------------------------
>
> Key: HBASE-5088
> URL: https://issues.apache.org/jira/browse/HBASE-5088
> Project: HBase
> Issue Type: Bug
> Components: client
> Affects Versions: 0.90.4, 0.94.0
> Reporter: Jieshan Bean
> Assignee: Jieshan Bean
> Attachments: 5088-useMapInterfaces.txt, 5088.generics.txt,
> HBase-5088-90.patch, HBase-5088-trunk.patch, HBase5088Reproduce.java
>
>
> SoftValueSortedMap is backed by a TreeMap. All the methods in this class are
> synchronized. If we use this method to add/delete elements, it's ok.
> But in HConnectionManager#getCachedLocation, it use headMap to get a view
> from SoftValueSortedMap#internalMap. Once we operate
> on this view map(like add/delete) in other threads, a concurrency issue may
> occur.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
