Client hangs and server gets unavailable

[Nuno Rodrigues]

Hello all,   I’m using Axis2 and Sandesha2 and I’m having a strange problem.   I have a client that wants to make 10000 requests but at the middle of all these requests (sometimes it only makes 300 requests, other times it makes 700,1000,…) the server crashes and there’s no more availability from the server side. I must say that the client doesn’t throw any kind of exception.   ----------------------------------------------------------------------------------------------------------------------------   If I browse to http://host:8080/axis2 everything seems ok but if I click the listServices link I get:    HTTP Status 500 -      type Status report      message      description The server encountered an internal error () that prevented    it from fulfilling this request.     Apache Tomcat/5.5.17     ----------------------------------------------------------------------------------------------------------------------------   Looking at apache Logs I have:   (…) INFO: Server startup in 4749 ms   (This is where the server hangs)   - I/O exception (org.apache.commons.httpclient.NoHttpResponseException) caught when processing request: The server 192.168.200.40 failed to respond - Retrying request - I/O exception (java.net.ConnectException) caught when processing request: Connection refused - Retrying request - I/O exception (java.net.ConnectException) caught when processing request: Connection refused - Retrying request   (Down here is when I try to access the list Services link)   - Servlet.service() for servlet jsp threw exception java.lang.NullPointerException         at org.apache.jsp.axis2_002dweb.listServices_jsp._jspService(listServices_jsp.java:133) (…) - Error dispatching request /axis2/services/listServices java.lang.reflect.InvocationTargetException         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) (…)     ----------------------------------------------------------------------------------------------------------------------------     The client code is:            //Generate Payload          OMFactory fac = OMAbstractFactory.getOMFactory();          OMNamespace omNs = fac.createOMNamespace("http://client.org/calculator2", "calculator2");          payload = fac.createOMElement("add", omNs);          rand1=(int)(Math.random()*100);          rand2=(int)(Math.random()*100);            // Send num1 num2 timestamp message id          payload.setText(rand1+" "+rand2+" "+ System.currentTimeMillis()+" "+i);            if (i==NUM_REQUESTS-1)            clientOptions.setProperty(SandeshaClientConstants.LAST_MESSAGE,"true");            // Async invocation          serviceClient.sendReceiveNonBlocking(payload,callback);            //Wait till the callback receives the response.          while (!callback.isComplete()) {             Thread.sleep(1);          }       Any idea to solve the problem?   Best regards,   Nuno Rodrigues