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Christian Liebhardt updated DROOLS-3412:
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Attachment: gc.png
Performance degradation with session pools
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Key: DROOLS-3412
URL:
https://issues.jboss.org/browse/DROOLS-3412
Project: Drools
Issue Type: Bug
Reporter: Christian Liebhardt
Assignee: Mario Fusco
Priority: Major
Attachments: gc.png
Hello,
We've today updates to Drools 7.15 and as discussed with DROOLS-3228 we changed our
code from calling _StatefulKnowledgeSessionImpl.reset_ ourselves to _KieSessionsPool_.
However we then recognized that our application quickly became slower and slower over time
(roughly after a few minutes of uptime, or a couple of hundred session create/dispose
cycles).
I haven't yet found the reason what is causing the slow down. However I think there
is a difference in how we reset our sessions before session pools and how session pools do
it. Perhaps that is a lead.
*What we did*
# Create a session
# Use the session
# Dispose and reset the session and go back to 2 for the next facts
*What happens with session pools*
# Create a session
# Use the session
# Skip dispose (because of _pool != null_ in the dispose method), reset the session and
go back to 2 for the next facts
So the difference seems to be that with session pools the session doesn't get
disposed before reset it called. If I do the same without session pools then I also see
the same slow down. So it seems that something is left behind and causes a slow down. The
results however seem to be correct, so the right consequences appear to be triggered.
An example on how we use the session pool can be found here:
https://github.com/liebharc/JavaRules/blob/master/src/main/java/com/githu...
Thanks once more for your help.