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https://issues.apache.org/jira/browse/DERBY-1781?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12534241
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Thomas Nielsen commented on DERBY-1781:
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The issue does not explicitly state, but I assume 1.5.0_05 where this was
reported also was a Sun JVM.
I tried reproducing this issue on the main trunk, and with a few different Sun
JVMs:
- 1.5.0_07
- 1.5.0_13
- 1.6.0_03
I fired up a network server on each and ran the repro script using the same
java version. The network server java process was monitored using the
SysInternals "Process Explorer"
(http://www.microsoft.com/technet/sysinternals/ProcessesAndThreads/ProcessExplorer.mspx)
While the repro runs I see the number of handles increasing, and they end at a
higher level than at the start as indicated in the report. All JVMs follow the
same pattern, but there's a tendency for newer JVMs to increase less (not
verified!). Ballpark numbers on handle count for the network server java
process is as follows:
Starting the network server: --> 350 handles.
Running the script a few times gives:
1st run: --> 580
2nd run: --> 600
3rd run: --> 610
The large increase on the first run is most likely due to population.
I believe some more investigation is in order.
> Process handles appear to be leaking in queries using an IN clause during
> concurrent DB access
> ----------------------------------------------------------------------------------------------
>
> Key: DERBY-1781
> URL: https://issues.apache.org/jira/browse/DERBY-1781
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.1.3.1
> Environment: Windows XP, Java 1.5.0_05
> Reporter: Mark Hellkamp
> Attachments: SqlStressTest.java
>
>
> We are currently using Derby embedded in our web application running on
> Windows. When processing multiple concurrent requests we have noticed that
> the Java process handle count continues to increase until the machine becomes
> unresponsive. I was able to isolate the problem to Derby by running the
> database in network mode in another process. Further investigation showed
> that the problem could be reproduced using a select statement that has an IN
> clause with multiple entries on the primary key column. Spawning multiple
> threads running the same query causes the handle count to increase
> considerably on the Derby process. The problem occurs in version 10.1.3.1 and
> 10.2.1.1 (even worse) in both embedded and network mode. The attached test
> program duplicates the problem. Start Derby in network mode (using
> startNetworkServer.bat) and run the enclosed test program. The handle count
> on the Derby process will increase and never go down short of restarting
> Derby. Using 10.2.1.1 the handle count for the Derby process goes somewhere
> between 1400-1500 with just two threads in my environment.
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