RE: [Springframework-developer] Non Thread-safe hibernate session

[March, A. <am...@so...>]

Unfortunately, this is not the case here.  We are using jmeter with
unauthenticated requests and therefore put nothing in the httpsession.
Additionally, your example should take place with as little as 2
requests: one fetching the object and sticking it into the HttpSession,
the other trying to initialize its collections.   In our case, we have
to create a decent amount of load (~30 pages/sec) for the errors to
occur.  Any other ideas?

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________________________________

From: spr...@li...
[mailto:spr...@li...] On Behalf
Of Juergen Hoeller
Sent: Saturday, January 29, 2005 2:44 AM
To: spr...@li...
Subject: RE: [Springframework-developer] Non Thread-safe hibernate
session

=20

Actually, this can happen without either Spring or the ThreadLocal
mechanism breaking: One of your persistent objects might hold a lazy
persistent collection, which holds a reference to the Session that
originally loaded it.

=20

If you put such a persistent object into the HttpSession, for example,
the original request that loaded the object (in thread TPProcessor1)
will have completed and thus the Hibernate Session have been closed.
Now, if you take your persistent object out of the HttpSession again in
a new request (in thread TPProcessor7) and try to access it lazy
collection, it's gonna fail because the original Session has been
closed.

=20

So the "leak" where a Session reference got out of its original
request/thread context is your persistent object in the HttpSession
here. This is a well-known problem: To make lazy loading work here, you
need to attach the persistent object to the new Hibernate Session (via
lock or saveOrUpdate).

=20

Juergen

=20

=20

	-----Original Message-----
	From: spr...@li...
[mailto:spr...@li...]On Behalf
Of March, Andres
	Sent: Friday, January 28, 2005 8:27 PM
	To: spr...@li...
	Subject: [Springframework-developer] Non Thread-safe hibernate
session

	As you can see below, a thread, other than the one that had the
session created for it, tries to access a session but it has been closed
by the valid owner thread.  This only occurs under decent load.  There
must be some thread safety issue in Spring or the whole ThreadLocal idea
goes out the window.  Does anybody have any idea how this could occur?
I don't see how I could be misinterpreting this trace.

	=20

	FATAL (SessionImpl.java:528) - Constructor for session:
net.sf.hibernate.impl.SessionImpl@b72884 on thread : TP-Processor1

	FATAL (SessionFactoryImpl.java:342) - Session :
net.sf.hibernate.impl.SessionImpl@b72884 created for Thread :
TP-Processor1

	...later on...=20

	closing session : net.sf.hibernate.impl.SessionImpl@b72884 and
conn: com.mchange.v2.c3p0.impl.NewProxyConnection@4ad009 on Thread :
TP-Processor1

	...later on...

	net.sf.hibernate.HibernateException: Session is closed :
net.sf.hibernate.impl.SessionImpl@b72884 on thread : TP-Processor7

	        at
net.sf.hibernate.impl.SessionImpl.connection(SessionImpl.java:3313)

	        at
net.sf.hibernate.proxy.LazyInitializer.initialize(LazyInitializer.java:4
7)

	        at
net.sf.hibernate.proxy.LazyInitializer.initializeWrapExceptions(LazyInit
ializer.java:60)

	        at
net.sf.hibernate.proxy.LazyInitializer.getImplementation(LazyInitializer
.java:164)

	        at
net.sf.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializ
er.java:108)

	        at
com.sony.soe.guilds.model.GameCharacter$$EnhancerByCGLIB$$25b6cd13.getBi
oImage(<generated>)

	        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
Method)

	        at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.jav
a:39)

	        at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessor
Impl.java:25)

	        at java.lang.reflect.Method.invoke(Method.java:324)

	        at
org.apache.velocity.runtime.parser.node.PropertyExecutor.execute(Propert
yExecutor.java:111)

	        at
org.apache.velocity.util.introspection.UberspectImpl$VelGetterImpl.invok
e(UberspectImpl.java:300)

	        at
org.apache.velocity.runtime.parser.node.ASTIdentifier.execute(ASTIdentif
ier.java:157)

	        at
org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReferenc
e.java:175)

	        at
org.apache.velocity.runtime.parser.node.ASTReference.evaluate(ASTReferen
ce.java:307)

	        at
org.apache.velocity.runtime.parser.node.ASTNotNode.evaluate(ASTNotNode.j
ava:47)

	        at
org.apache.velocity.runtime.parser.node.ASTExpression.evaluate(ASTExpres
sion.java:46)

	        at
org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfState
ment.java:69)

	        at
org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.jav
a:231)

	        at
org.apache.velocity.runtime.directive.Parse.render(Parse.java:181)

	        at
org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective
.java:116)

	        at
org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:56
)

	        at
org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfState
ment.java:71)

	        at
org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:56
)

	        at
org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfState
ment.java:71)

	        at
org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.jav
a:231)

	        at
org.apache.velocity.runtime.directive.Parse.render(Parse.java:181)

	        at
org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective
.java:116)

	        at
org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.jav
a:231)

	        at org.apache.velocity.Template.merge(Template.java:256)

	        at
com.sony.soe.web.mvc.VelocityView.go(VelocityView.java:181)

	        at
com.sony.soe.guilds.view.VelocityLayout.go(VelocityLayout.java:135)

	        at
org.infohazard.maverick.flow.CommandBase.go(CommandBase.java:79)

	        at
org.infohazard.maverick.Dispatcher.service(Dispatcher.java:345)

	        at
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)

	        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Applica
tionFilterChain.java:237)

	        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilt
erChain.java:157)

	        at
net.sf.acegisecurity.ui.AbstractIntegrationFilter.doFilter(AbstractInteg
rationFilter.java:170)

	        at
com.sony.soe.guilds.controller.SecurityFilter.doFilter(SecurityFilter.ja
va:118)

	        at
net.sf.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.j
ava:88)

	        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Applica
tionFilterChain.java:186)

	        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilt
erChain.java:157)

	        at
org.springframework.orm.hibernate.support.OpenSessionInViewFilter.doFilt
erInternal(OpenSessionInViewFilter.java:17

	1)

	        at
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequ
estFilter.java:76)

	        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Applica
tionFilterChain.java:186)

	        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilt
erChain.java:157)

	        at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValv
e.java:214)

	        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveCo
ntext.java:104)

	        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:5
20)

	        at
org.apache.catalina.core.StandardContextValve.invokeInternal(StandardCon
textValve.java:198)

	        at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValv
e.java:152)

	        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveCo
ntext.java:104)

	        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:5
20)

	        at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java
:137)

	        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveCo
ntext.java:104)

	        at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java
:117)

	        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveCo
ntext.java:102)

	        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:5
20)

	        at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.
java:109)

	        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveCo
ntext.java:104)

	        at
org.apache.catalina.valves.RequestDumperValve.invoke(RequestDumperValve.
java:169)

	        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveCo
ntext.java:102)

	        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:5
20)

	        at
org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)

	        at
org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)

	        at
org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:296)

	        at
org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:372)

	        at
org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:694)

	        at
org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:
626)

	        at
org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:807)

	        at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool
.java:644)

	        at java.lang.Thread.run(Thread.java:534)

	=20

	-----------------------------------------

	Andres March

	Platform - Apps Engineering

	Sony Online Entertainment

	desk: 858.577.3373

	cell:   619.519.1519

	=20