getting inputstream canot be null for wso2 data service - wso2

Question

I am using wso2 esb 4.0.3 and created a wso2 data service which is calling a teradata procedure by passing two input parameters and getting 16 columns as response.
Sometimes it's giving the proper output but somtimes it's giving an error:
How can I can get constant response?
[2013-06-10 15:18:54,097] INFO - HTTPSender Unable to sendViaPost to url[http://localhost:8280/services/SampleSemsDataService1.SOAP12Endpoint]
org.apache.axis2.AxisFault: InputStream cannot be NULL.
at org.apache.axis2.transport.http.AbstractHTTPSender.processResponse(AbstractHTTPSender.java:219)
at org.apache.axis2.transport.http.HTTPSender.handleResponse(HTTPSender.java:271)
at org.apache.axis2.transport.http.HTTPSender.sendViaPost(HTTPSender.java:194)
at org.apache.axis2.transport.http.HTTPSender.send(HTTPSender.java:75)
at org.apache.axis2.transport.http.CommonsHTTPTransportSender.writeMessageWithCommons(CommonsHTTPTransportSender.java:449)
at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:276)
at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:443)
at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:406)
at org.apache.axis2.description.OutInAxisOperationClient.executeImpl(OutInAxisOperation.java:229)
at org.apache.axis2.client.OperationClient.execute(OperationClient.java:165)
at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:555)
at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:531)
at org.apache.jsp.admin.jsp.WSRequestXSSproxy_005fajaxprocessor_jsp._jspService(WSRequestXSSproxy_005fajaxprocessor_jsp.java:272)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.wso2.carbon.ui.JspServlet.service(JspServlet.java:161)
at org.wso2.carbon.ui.TilesJspServlet.service(TilesJspServlet.java:80)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.eclipse.equinox.http.helper.ContextPathServletAdaptor.service(ContextPathServletAdaptor.java:36)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.handleRequest(ServletRegistration.java:90)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:111)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:67)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.wso2.carbon.bridge.BridgeServlet.service(BridgeServlet.java:164)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.wso2.carbon.server.CarbonStuckThreadDetectionValve.invoke(CarbonStuckThreadDetectionValve.java:154)
at org.wso2.carbon.server.TomcatServer$1.invoke(TomcatServer.java:254)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:399)
at org.apache.coyote.http11.Http11NioProcessor.process(Http11NioProcessor.java:396)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:356)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1534)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:680)
[2013-06-10 15:19:02,764] WARN - HttpCoreNIOSender Connection closed by client : 127.0.0.1

Answer 1

HTTPSender Unable to sendViaPost to url[http://localhost:8280/services/SampleSemsDataService1.SOAP12Endpoint]
Your data service runs on port 8280? Did you install DS feature in ESB? if so, you should use servlet transport (port 9763/9443)not the NIO transport