Hi Ingomar, <br><br>Which drools version are you using? We made improvements on 4.0.4, that fixes concurrency issues on mvel core, so if you aren't using it please do an update and try test against your environment. <br>
<br>Please let me know if your problems go away when you upgrade.<br><br>Thanks <br><br><div class="gmail_quote">On Jan 22, 2008 11:13 AM, Ingomar Otter <<a href="mailto:ingomar.otter@valtech.de">ingomar.otter@valtech.de
</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div><div style="">Folks,<div>I am currently
trying to scale our implementation by farming out request into mutliple
threads. I am on a 4 CPU Mac.</div><div>A few things I am wondering
about:</div><div>1. Although I see an increase in CPU load when going from
single to multi-threaded processing the throughput increased marginally. I
am pretty sure that my measurements are correct. I have checked the
GC and this is not the source of congestion. My question here is whether
Drools is using lot's of synchronization that may explain
this. </div><div>2. When I share the RuleBase accross threads (which
I think is valid?) I get interesting errors
during execution. eg:</div><div><div style="margin: 0px; min-height: 15px;"><br></div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="text-decoration: underline; color: rgb(0, 0, 128);">org.drools.RuntimeDroolsException
</span>: Exception executing
predicate org.drools.base.mvel.MVELPredicateExpression@bb981e</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"></span>atorg.drools.rule.PredicateConstraint.isAllowedCachedRight(<span style="text-decoration: underline; color: rgb(0, 0, 128);">
PredicateConstraint.java:246</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>at
org.drools.common.TripleBetaConstraints.isAllowedCachedRight(<span style="text-decoration: underline; color: rgb(0, 0, 128);">TripleBetaConstraints.java:200</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>atorg.drools.reteoo.JoinNode.assertObject(<span style="text-decoration: underline; color: rgb(0, 0, 128);">JoinNode.java:150</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>atorg.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(<span style="text-decoration: underline; color: rgb(0, 0, 128);">CompositeObjectSinkAdapter.java:318</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);">
<span style="white-space: pre;"></span>atorg.drools.reteoo.ObjectTypeNode.assertObject(<span style="text-decoration: underline; color: rgb(0, 0, 128);">ObjectTypeNode.java:153</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);">
<span style="white-space: pre;"> </span>at
org.drools.reteoo.Rete.assertObject(<span style="text-decoration: underline; color: rgb(0, 0, 128);">Rete.java:175</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"></span>atorg.drools.reteoo.ReteooRuleBase.assertObject
(<span style="text-decoration: underline; color: rgb(0, 0, 128);">ReteooRuleBase.java:192</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>at
org.drools.reteoo.ReteooWorkingMemory.doInsert(<span style="text-decoration: underline; color: rgb(0, 0, 128);">ReteooWorkingMemory.java:71</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>at
org.drools.common.AbstractWorkingMemory.insert(<span style="text-decoration: underline; color: rgb(0, 0, 128);">AbstractWorkingMemory.java:909</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>atorg.drools.common.AbstractWorkingMemory.insert(<span style="text-decoration: underline; color: rgb(0, 0, 128);">AbstractWorkingMemory.java:881</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>atorg.drools.common.AbstractWorkingMemory.insert(<span style="text-decoration: underline; color: rgb(0, 0, 128);">AbstractWorkingMemory.java:682</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>atxxxx.DroolsPD.validate(<span style="text-decoration: underline; color: rgb(0, 0, 128);">DroolsPD.java:66</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>at
xxxx.DroolsMTRunner.run(<span style="text-decoration: underline; color: rgb(0, 0, 128);">DroolsMTRunner.java:30</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>at
java.lang.Thread.run(<span style="text-decoration: underline; color: rgb(0, 0, 128);">Thread.java:552</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);">Caused by:
<span style="text-decoration: underline; color: rgb(0, 0, 128);">org.mvel.CompileException</span>: cannot invoke getter:
getSAClass [declr.class: xxx.AbstractSA; act.class: null]</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"></span>atorg.mvel.optimizers.impl.refl.GetterAccessor.getValue(<span style="text-decoration: underline; color: rgb(0, 0, 128);">
GetterAccessor.java:52</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>at
org.mvel.optimizers.impl.refl.VariableAccessor.getValue(<span style="text-decoration: underline; color: rgb(0, 0, 128);">VariableAccessor.java:39</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>at
org.mvel.ast.VariableDeepPropertyNode.getReducedValueAccelerated(<span style="text-decoration: underline; color: rgb(0, 0, 128);">VariableDeepPropertyNode.java:22</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);">
<span style="white-space: pre;"></span>atorg.mvel.ast.PropertyASTNode.getReducedValueAccelerated(<span style="text-decoration: underline; color: rgb(0, 0, 128);">PropertyASTNode.java:21</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);">
<span style="white-space: pre;"> </span>at
org.mvel.ast.BinaryOperation.getReducedValueAccelerated(<span style="text-decoration: underline; color: rgb(0, 0, 128);">BinaryOperation.java:21</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>at
org.mvel.MVELRuntime.execute(<span style="text-decoration: underline; color: rgb(0, 0, 128);">MVELRuntime.java:88</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>at
org.mvel.CompiledExpression.getValue(<span style="text-decoration: underline; color: rgb(0, 0, 128);">CompiledExpression.java:111</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>atorg.mvel.MVEL.executeExpression(<span style="text-decoration: underline; color: rgb(0, 0, 128);">MVEL.java:235</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>
at
org.drools.base.mvel.MVELPredicateExpression.evaluate(<span style="text-decoration: underline; color: rgb(0, 0, 128);">MVELPredicateExpression.java:36</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>atorg.drools.rule.PredicateConstraint.isAllowedCachedRight(<span style="text-decoration: underline; color: rgb(0, 0, 128);">PredicateConstraint.java:240</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);">
<span style="white-space: pre;"> </span>... 13
more</div><div style="margin: 0px; color: rgb(0, 0, 128);"><span style="color: rgb(255, 0, 0);">Caused by:
</span><span style="text-decoration: underline;">java.lang.NullPointerException</span></div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"></span>atsun.reflect.GeneratedMethodAccessor6.invoke
(Unknown Source)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"></span>atsun.reflect.DelegatingMethodAccessorImpl.invoke(<span style="text-decoration: underline; color: rgb(0, 0, 128);">
DelegatingMethodAccessorImpl.java:25</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"></span>atjava.lang.reflect.Method.invoke(<span style="text-decoration: underline; color: rgb(0, 0, 128);">
Method.java:324</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;"> </span>at
org.mvel.optimizers.impl.refl.GetterAccessor.getValue(<span style="text-decoration: underline; color: rgb(0, 0, 128);">GetterAccessor.java:42</span>)</div><div style="margin: 0px; color: rgb(255, 0, 0);"><span style="white-space: pre;">
</span>... 22
more</div></div><div><br></div><div>Details:</div><div> * I
use StatelessSessions which are private to the threads</div><div> *
No data is shared between threads (with the exception of the RuleBase, as
outline above)</div><div> * I am on JDK 1.5</div><div><br></div><div>I would be grateful for any
pointers for 'correct' use of Drools in an MT
environment.</div><div>Cheers,</div><div> Ingomar</div></div><br></div>
<div style="font-size: 8pt; color: rgb(128, 128, 128); line-height: 100%; font-family: Arial,Helvetica,sans-serif;"><span style="font-weight: bold; font-size: 9pt; color: rgb(0, 0, 0);"><br>Ingomar Otter</span><br><span style="font-weight: bold; font-size: 9pt; color: rgb(255, 135, 10);">
Chief Technology
Officer</span><br><a href="mailto:ingomar.otter@valtech.de" target="_blank">ingomar.otter@valtech.de</a><br>Mobile: +49 172
2367867<br><br><span style="font-weight: bold; font-size: 9pt; color: rgb(0, 0, 0);">Valtech GmbH</span><br>Bahnstraße 16<br>40212
Düsseldorf<br>Germany<br><br>Phone: +49 (0)211 179237-0<br>Fax: +49
211 179237-19<br><br><a style="color: rgb(128, 128, 128);" href="http://www.valtech.de/" target="_blank">www.valtech.de</a><br><br>Geschäftsführer:
Ingo Kriescher<br>Amtsgericht Düsseldorf HRB48672</div>
<br>
<div>
</div></div>
<br>_______________________________________________<br>rules-users mailing list<br><a href="mailto:rules-users@lists.jboss.org">rules-users@lists.jboss.org</a><br><a href="https://lists.jboss.org/mailman/listinfo/rules-users" target="_blank">
https://lists.jboss.org/mailman/listinfo/rules-users</a><br><br></blockquote></div><br><br clear="all"><br>-- <br>Fernando Meyer <a href="http://fmeyer.org">http://fmeyer.org</a><br>JBoss Rules Core Developer<br><a href="mailto:fernando@fmeyer.org">
fernando@fmeyer.org</a>