Dear all,

we are using a synchronous sendAndReceiveCAS() call within a webservice 
endpoint (JAX WS RI).
Doing so, in some cases we find hanging requests, which are not getting 
completed.
I am attaching a corresponding part of a thread dump.

We are using UIMA AS 2.4.0. Application environment is Tomcat 6.0.32, 
JAX WS RI 2.1.7.

Have you encountered a similar behaviour?

Thank and all the best
Frank

"catalina-exec-77" Id=3412437 in WAITING cpu=2083520 ms usr=2056580 ms 
blocked 547742 for -1 ms waited 297560 for -1 ms
     locks java.util.concurrent.locks.ReentrantLock$NonfairSync@19c88785
     at sun.misc.Unsafe.park(Native Method)
     - waiting on (a java.util.concurrent.Semaphore$NonfairSync@3c3939fc)
     at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156)
     at 
java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811)
     at 
java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969)
     at 
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281)
     at java.util.concurrent.Semaphore.acquire(Semaphore.java:286)
     at 
org.apache.uima.adapter.jms.client.BaseUIMAAsynchronousEngineCommon_impl.sendAndReceiveCAS(BaseUIMAAsynchronousEngineCommon_impl.java:2062)
     at 
org.apache.uima.adapter.jms.client.BaseUIMAAsynchronousEngineCommon_impl.sendAndReceiveCAS(BaseUIMAAsynchronousEngineCommon_impl.java:1952)
     at 
de.averbis.extraction.[...].webservice.WebservicePort.getLanguage(WebservicePort.java:1214)
     at sun.reflect.GeneratedMethodAccessor2765.invoke(Unknown Source)
     at 
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     at java.lang.reflect.Method.invoke(Method.java:597)
     at 
com.sun.xml.ws.api.server.InstanceResolver$1.invoke(InstanceResolver.java:246)
     at com.sun.xml.ws.server.InvokerTube$2.invoke(InvokerTube.java:146)
     at 
com.sun.xml.ws.server.sei.EndpointMethodHandler.invoke(EndpointMethodHandler.java:257)
     at 
com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:93)
     at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:598)
     at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:557)
     at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:542)
     at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:439)
     - locked (a com.sun.xml.ws.api.pipe.Fiber@5a8fe32) index 19 frame 
com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:439)
     at 
com.sun.xml.ws.server.WSEndpointImpl$2.process(WSEndpointImpl.java:243)
     at 
com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:471)
     at 
com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:244)
     at 
com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:135)
     at 
com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doGet(WSServletDelegate.java:129)
     at 
com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doPost(WSServletDelegate.java:160)
     at 
com.sun.xml.ws.transport.http.servlet.WSServlet.doPost(WSServlet.java:75)
     at javax.servlet.http.HttpServlet.service(Unknown Source)
     at javax.servlet.http.HttpServlet.service(Unknown Source)
     at 
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown 
Source)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown 
Source)
     at org.apache.catalina.core.StandardWrapperValve.invoke(Unknown Source)
     at org.apache.catalina.core.StandardContextValve.invoke(Unknown Source)
     at org.apache.catalina.core.StandardHostValve.invoke(Unknown Source)
     at org.apache.catalina.valves.ErrorReportValve.invoke(Unknown Source)
     at org.apache.catalina.valves.AccessLogValve.invoke(Unknown Source)
     at org.apache.catalina.core.StandardEngineValve.invoke(Unknown Source)
     at org.apache.catalina.connector.CoyoteAdapter.service(Unknown Source)
     at org.apache.coyote.ajp.AjpAprProcessor.process(Unknown Source)
     at 
org.apache.coyote.ajp.AjpAprProtocol$AjpConnectionHandler.process(Unknown Source)
     at 
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(Unknown Source)
     at 
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
     at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
     at java.lang.Thread.run(Thread.java:662)