<font size=2 face="sans-serif">Hi , </font>
<br>
<br><font size=2 face="sans-serif">We have noted another incident
in our testing environment where we have noted that there
is a concurrency issue with the drools and mvel version we are using
where the threads are blocked for a long time resulting the
application node/JVM reach an unexpected state which
needed to be restarted.Could some one look into this if there
is a known defect on this and if it has been resolved in a later version?.</font>
<br>
<br><font size=2 face="sans-serif">Thread[DSLFpmlDataRecordKeepingTradeViewCacheWorker:5,5,DSLFpmlDataRecordKeepingTradeViewCache]</font>
<br><font size=2 face="sans-serif"> java.util.WeakHashMap.get(WeakHashMap.java:470)</font>
<br><font size=2 face="sans-serif"> org.mvel2.util.ParseTools.getBestCandidate(ParseTools.java:246)</font>
<br><font size=2 face="sans-serif"> org.mvel2.util.ParseTools.getBestCandidate(ParseTools.java:224)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.PropertyVerifier.getMethod(PropertyVerifier.java:509)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.PropertyVerifier.analyze(PropertyVerifier.java:120)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.ExpressionCompiler.verify(ExpressionCompiler.java:381)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.ExpressionCompiler._compile(ExpressionCompiler.java:273)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.ExpressionCompiler.compile(ExpressionCompiler.java:62)</font>
<br><font size=2 face="sans-serif"> org.mvel2.MVEL.compileExpression(MVEL.java:810)</font>
<br><font size=2 face="sans-serif"> org.drools.base.mvel.MVELCompilationUnit.compile(MVELCompilationUnit.java:426)</font>
<br><font size=2 face="sans-serif"> org.drools.base.mvel.MVELCompilationUnit.getCompiledExpression(MVELCompilationUnit.java:243)</font>
<br><font size=2 face="sans-serif"> org.drools.base.dataproviders.MVELDataProvider.compile(MVELDataProvider.java:83)</font>
<br><font size=2 face="sans-serif"> org.drools.rule.MVELDialectRuntimeData.onBeforeExecute(MVELDialectRuntimeData.java:162)</font>
<br><font size=2 face="sans-serif"> org.drools.rule.DialectRuntimeRegistry.onBeforeExecute(DialectRuntimeRegistry.java:138)</font>
<br><font size=2 face="sans-serif"> org.drools.common.AbstractRuleBase.readExternal(AbstractRuleBase.java:295)</font>
<br><font size=2 face="sans-serif"> org.drools.reteoo.ReteooRuleBase.readExternal(ReteooRuleBase.java:223)</font>
<br><font size=2 face="sans-serif"> org.drools.impl.KnowledgeBaseImpl.readExternal(KnowledgeBaseImpl.java:116)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1835)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1794)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)</font>
<br>
<br>
<br>
<br><font size=2 face="sans-serif">Thread[DSLFpmlDataRecordKeepingCacheWorker:39,5,DSLFpmlDataRecordKeepingCache]</font>
<br><font size=2 face="sans-serif"> java.util.WeakHashMap.expungeStaleEntries(WeakHashMap.java:386)</font>
<br><font size=2 face="sans-serif"> java.util.WeakHashMap.getTable(WeakHashMap.java:417)</font>
<br><font size=2 face="sans-serif"> java.util.WeakHashMap.get(WeakHashMap.java:464)</font>
<br><font size=2 face="sans-serif"> org.mvel2.util.ParseTools.getBestCandidate(ParseTools.java:246)</font>
<br><font size=2 face="sans-serif"> org.mvel2.util.ParseTools.getBestCandidate(ParseTools.java:224)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.PropertyVerifier.getMethod(PropertyVerifier.java:509)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.PropertyVerifier.analyze(PropertyVerifier.java:120)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.ExpressionCompiler.verify(ExpressionCompiler.java:381)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.ExpressionCompiler._compile(ExpressionCompiler.java:273)</font>
<br><font size=2 face="sans-serif"> org.mvel2.compiler.ExpressionCompiler.compile(ExpressionCompiler.java:62)</font>
<br><font size=2 face="sans-serif"> org.mvel2.MVEL.compileExpression(MVEL.java:810)</font>
<br><font size=2 face="sans-serif"> org.drools.base.mvel.MVELCompilationUnit.compile(MVELCompilationUnit.java:426)</font>
<br><font size=2 face="sans-serif"> org.drools.base.mvel.MVELCompilationUnit.getCompiledExpression(MVELCompilationUnit.java:243)</font>
<br><font size=2 face="sans-serif"> org.drools.base.mvel.MVELPredicateExpression.compile(MVELPredicateExpression.java:69)</font>
<br><font size=2 face="sans-serif"> org.drools.rule.MVELDialectRuntimeData.onBeforeExecute(MVELDialectRuntimeData.java:162)</font>
<br><font size=2 face="sans-serif"> org.drools.rule.DialectRuntimeRegistry.onBeforeExecute(DialectRuntimeRegistry.java:138)</font>
<br><font size=2 face="sans-serif"> org.drools.common.AbstractRuleBase.readExternal(AbstractRuleBase.java:295)</font>
<br><font size=2 face="sans-serif"> org.drools.reteoo.ReteooRuleBase.readExternal(ReteooRuleBase.java:223)</font>
<br><font size=2 face="sans-serif"> org.drools.impl.KnowledgeBaseImpl.readExternal(KnowledgeBaseImpl.java:116)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1835)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1794)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)</font>
<br><font size=2 face="sans-serif"> java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)</font>
<br>
<br><font size=2 face="sans-serif">We have found a similar BUG in the drools
defect database </font>
<br><a href="https://issues.jboss.org/i#browse/DROOLS-81"><font size=2 face="sans-serif">https://issues.jboss.org/i#browse/DROOLS-81</font></a><font size=2 face="sans-serif">
but the scenarios are bit different.</font>
<br>
<br><font size=2 face="sans-serif">In our case it has happened when we
deserialize the serilized KnowledgeBaseImpl by multiple threads
and it seems that the problem is due to usage of a java.util.WeakHashMap
as a class variable in</font>
<br>
<br><font size=2 face="sans-serif"> org.mvel2.util.ParseTools.getBestCandidate(ParseTools.java:246)</font>
<br>
<br>
<br>
<br><font size=2 face="sans-serif">Thanks<br>
&<br>
Regards,<br>
Adarsh <br>
<br>
SENIOR LEAD DEVELOPMENT SPECIALIST<br>
SCJP, SCWCD <br>
FINANCE TECHNOLOGY<br>
HSBC BANK PLC HBEU<br>
8 Canada Square,Canary Wharf,<br>
London,E14 5HQ,United Kingdom<br>
------------------------------------------------------<br>
Phone +44 207914720<br>
Mobile 07595530105<br>
Email. adarsh.chaini@hsbcib.com<br>
________________________________</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">From:</font>
<td><font size=1 face="sans-serif">Imran Shafiq <ishafiq@redhat.com></font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">To:</font>
<td><font size=1 face="sans-serif">Adarsh CHAINI/IBEU/HSBC@HSBC</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Date:</font>
<td><font size=1 face="sans-serif">17/09/2013 18:55</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Subject:</font>
<td><font size=1 face="sans-serif">Drools Community Issue.</font></table>
<br>
<hr noshade>
<br>
<br>
<br><font size=2 face="Arial">Hi Ardash,</font>
<br>
<br><font size=2 face="Arial">I've seen details of the recent issue you
have experienced with the community Drools product; I was keen to contact
you regarding this.</font>
<br>
<br><font size=2 face="Arial">We have been a strategic and global supplier
to HSBC for many years, and have built our success largely on our ability
to provide full enterprise services and productised versions of community
products, that are fit for enterprise use.</font>
<br>
<br><font size=2 face="Arial">In the case of community Drools, our productised
version (JBoss BRMS) provides a full testing, certification, commercial
assurance eco-system, and 24*7 SLA support service - which would appear
to be ideally positioned to help address issues such as that which you
are currently experiencing.</font>
<br>
<br><font size=2 face="Arial">Ardash, given the appetite of HSBC to mitigate
the risk associated with the use of community software alone, I would welcome
the opportunity to have a brief initial conversation with you concerning
the above.</font>
<br>
<br><font size=2 face="Arial">Might there be a suitable number for me to
reach you in the coming days?</font>
<br>
<br><font size=2 face="Arial">Kind regards</font>
<br>
<br><font size=2 face="Arial">Imran</font>
<br>
<br><font size=2 face="Arial">Imran Shafiq<br>
Strategic & Global Accounts Team <br>
Red Hat UK<br>
Direct: +44 (0) 1252 362766<br>
Mobile: +44 (0) 7506 765 287<br>
ishafiq@redhat.com<br>
</font><a href=www.europe.redhat.com><font size=2 face="Arial">www.europe.redhat.com</font></a>
<br>
<br><font size=2 face="Arial"><br>
</font>
<br>
<br>
<br><font size=2 face="sans-serif"><br>
<br>
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