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We are encountering many threads waiting behind the below thread which owns the ClassLoader lock as shown.

This is happening on Weblogic 10.3.6 running on IBM JDK 1.7.

I have considered swapping out the Weblogic JAX-WS implementation with a newer one, but would like some evidence that it will resolve the problem before embarking down that path.

I also see here Is this JAX-WS client call thread safe? that the proxy classes are not thread safe. What about using ThreadLocal instances of the proxy classes? Or a pool of proxy classes similiar to KryoPool?

https://github.com/EsotericSoftware/kryo/blob/master/src/com/esotericsoftware/kryo/pool/KryoPool.java

Monitor

Owns Monitor Lock on 
java/lang/ClassLoader$ClassNameBasedLock@0x00000007D0BB0B18 , java/util/jar/JarFile@0x000000070300BD08

Java Stack

at java/util/zip/ZipFile.getEntryByModifiedUTF8(Native Method) 
at java/util/zip/ZipFile.getEntry(ZipFile.java:343(Compiled Code)) 
at java/util/jar/JarFile.getEntry(JarFile.java:305(Compiled Code)) 
at java/util/jar/JarFile.getJarEntry(JarFile.java:288(Compiled Code)) 
at sun/misc/URLClassPath$JarLoader.getResource(URLClassPath.java:1093(Compiled Code)) 
at sun/misc/URLClassPath.getResource(URLClassPath.java:330(Compiled Code)) 
at java/net/URLClassLoader$ClassFinder.run(URLClassLoader.java:1162(Compiled Code)) 
at java/security/AccessController.doPrivileged(AccessController.java:488) 
at java/net/URLClassLoader.findClass(URLClassLoader.java:595(Compiled Code)) 
at java/lang/ClassLoader.loadClassHelper(ClassLoader.java:786(Compiled Code)) 
at java/lang/ClassLoader.loadClass(ClassLoader.java:760(Compiled Code)) 
at sun/misc/Launcher$AppClassLoader.loadClass(Launcher.java:326(Compiled Code)) 
at java/lang/ClassLoader.loadClassHelper(ClassLoader.java:778(Compiled Code)) 
at java/lang/ClassLoader.loadClass(ClassLoader.java:764(Compiled Code)) 
at java/lang/ClassLoader.loadClass(ClassLoader.java:741(Compiled Code)) 
at com/sun/proxy/$Proxy162191.getCustomerDetails(Bytecode PC:21) 
at sun/reflect/GeneratedMethodAccessor574.invoke(Bytecode PC:42(Compiled Code)) 
at sun/reflect/DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:56(Compiled Code)) 
at java/lang/reflect/Method.invoke(Method.java:620(Compiled Code)) 
at weblogic/wsee/jaxws/spi/ClientInstanceInvocationHandler.invoke(ClientInstanceInvocationHandler.java:84(Compiled Code)) 
at com/sun/proxy/$Proxy636.getCustomerDetails(Bytecode PC:18(Compiled Code)) 
at sun/reflect/GeneratedMethodAccessor574.invoke(Bytecode PC:42(Compiled Code)) 
at sun/reflect/DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:56(Compiled Code)) 
at java/lang/reflect/Method.invoke(Method.java:620(Compiled Code)) 
at com/mycompany/util/webservice/PortFactory$PortCacheProxy.callMethodOnPort(PortFactory.java:317(Compiled Code)) 
at com/mycompany/util/webservice/PortFactory$PortCacheProxy.invoke(PortFactory.java:290(Compiled Code)) 
at com/sun/proxy/$Proxy637.getCustomerDetails(Bytecode PC:18(Compiled Code)) 
at com/mycompany/wsclient/customer/viewcustomerdetails/GetCustomerDetailsBaseOperation.call(GetCustomerDetailsBaseOperation.java:52(Compiled Code)) 
at com/mycompany/wsclient/customer/viewcustomerdetails/GetCustomerDetailsBaseOperation.call(GetCustomerDetailsBaseOperation.java:19(Compiled Code)) 
at com/mycompany/util/webservice/WebServiceOperation.call(WebServiceOperation.java:261(Compiled Code)) 
at com/mycompany/util/webservice/WebServiceOperationWork.run(WebServiceOperationWork.java:27(Compiled Code)) 
at weblogic/work/j2ee/J2EEWorkManager$WorkWithListener.run(J2EEWorkManager.java:184(Compiled Code)) 
at weblogic/work/ExecuteThread.execute(ExecuteThread.java:263(Compiled Code)) 
at weblogic/work/ExecuteThread.run(ExecuteThread.java:221(Compiled Code))
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rudolfv
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  • Does the app hang at this point or does it eventually make progress? How often does this happen: only the first time a class is loaded or more frequently? – Dan Heidinga Nov 25 '16 at 06:03
  • In this case the server transitioned to a failed state. Our threshold for marking a thread as STUCK is 60 seconds and the count for transitioning to failed state is a 100 STUCK threads. This happens intermittently in production specifically with the JAX-WS proxy classes, I haven't seen it happen with other code since we upgraded to JDK 1.7. – rudolfv Nov 25 '16 at 12:00

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