Exception under load

[Vignesh.kc@gmail.com]

Hi , I get the following exception when I run my service under heavy load.

[08-22-07:21:46:31- (WARN )] org.springframework.ws.soap.server.SoapMessageDispatcher  : Endpoint invocation resulted in exception - responding with SOAP Fault
java.util.ConcurrentModificationException
        at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:449)
        at java.util.AbstractList$Itr.next(AbstractList.java:420)
        at org.dom4j.io.SAXWriter.writeContent(SAXWriter.java:616)
        at org.dom4j.io.SAXWriter.write(SAXWriter.java:733)
        at org.dom4j.io.SAXWriter.writeContent(SAXWriter.java:619)
        at org.dom4j.io.SAXWriter.write(SAXWriter.java:733)
        at org.dom4j.io.SAXWriter.writeContent(SAXWriter.java:619)
        at org.dom4j.io.SAXWriter.write(SAXWriter.java:202)
        at org.dom4j.io.SAXWriter.parse(SAXWriter.java:603)
        at org.apache.xalan.transformer.TransformerIdentityImpl.transform(TransformerIdentityImpl.java:484)
        at org.springframework.ws.server.endpoint.PayloadEndpointAdapter.invoke(PayloadEndpointAdapter.java:47)
        at org.springframework.ws.server.MessageDispatcher.dispatch(MessageDispatcher.java:205)
        at org.springframework.ws.server.MessageDispatcher.receive(MessageDispatcher.java:166)
        at org.springframework.ws.transport.support.WebServiceMessageReceiverObjectSupport.handle(WebServiceMessageReceiverObjectSupport.java:78)
        at org.springframework.ws.transport.http.WebServiceMessageReceiverHandlerAdapter.handle(WebServiceMessageReceiverHandlerAdapter.java:60)
        at org.springframework.ws.transport.http.MessageDispatcherServlet.doService(MessageDispatcherServlet.java:125)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:461)
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:426)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:763)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
        at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:225)
        at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:127)
        at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:272)
        at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:165)
        at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3153)
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
        at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
        at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:1973)
        at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1880)
        at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1310)
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:207)
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:179)

Have you experienced this ?

Thanks
Vignesh

[Arjen Poutsma]

It looks like dom4j has multiple threads accessing the same XML content. Do you spawn threads in your app, by any chance? If you are, that's probably not a good idea. If you don't, it's a bug in dom4j, which should be fixed by them.

[Vignesh.kc@gmail.com]

Hi I changed my implementation to jDOM and still get the same error.

It occurs when there are ~25 connections to the service at the same
moement.

Iam not spawing threads, i use the same servlet which comes with spring.

Please let me know your thoughts.

javax.xml.transform.TransformerException: java.util.ConcurrentModificationException
        at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:647)
        at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:279)
        at org.springframework.ws.server.endpoint.PayloadEndpointAdapter.invoke(PayloadEndpointAdapter.java:47)
        at org.springframework.ws.server.MessageDispatcher.dispatch(MessageDispatcher.java:205)
        at org.springframework.ws.server.MessageDispatcher.receive(MessageDispatcher.java:166)
        at org.springframework.ws.transport.support.WebServiceMessageReceiverObjectSupport.handle(WebServiceMessageReceiverObj
ectSupport.java:78)
        at org.springframework.ws.transport.http.WebServiceMessageReceiverHandlerAdapter.handle(WebServiceMessageReceiverHandl
erAdapter.java:60)
        at org.springframework.ws.transport.http.MessageDispatcherServlet.doService(MessageDispatcherServlet.java:125)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:461)
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:426)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:763)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
        at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:225)
        at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:127)
        at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:272)
        at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:165)
        at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3153)
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
        at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
        at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:1973)
        at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1880)
        at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1310)
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:207)
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:179)
Caused by: java.util.ConcurrentModificationException
        at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:449)
        at java.util.AbstractList$Itr.next(AbstractList.java:420)
        at org.jdom.output.SAXOutputter.elementContent(SAXOutputter.java:1064)
        at org.jdom.output.SAXOutputter.element(SAXOutputter.java:897)
        at org.jdom.output.SAXOutputter.elementContent(SAXOutputter.java:1093)
        at org.jdom.output.SAXOutputter.elementContent(SAXOutputter.java:1067)
        at org.jdom.output.SAXOutputter.element(SAXOutputter.java:897)
        at org.jdom.output.SAXOutputter.elementContent(SAXOutputter.java:1093)
        at org.jdom.output.SAXOutputter.elementContent(SAXOutputter.java:1067)
        at org.jdom.output.SAXOutputter.output(SAXOutputter.java:666)
        at org.jdom.transform.JDOMSource$DocumentReader.parse(JDOMSource.java:479)
        at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transformIdentity(TransformerImpl.java:584)
        at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:638)
        ... 23 more

Thanks we are failing in our load testing. Any help is appreciated.

Thanks
Vignesh

[Vignesh.kc@gmail.com]

I got rid of it.

I was making a response document and getting the root element returned,
I refactored just to make the root element and it worked.