Hi,
I've built a GIS FLEX application that uses blazeDS' messaging
capability to push location (latitude/longitude/geocode) info to flex
clients.
The message producer is a custom Java bootstrapper and adapter that
configures the messaging destination endpoints upon server startup.
The destination runtime config java bootstrap method for our
"fleet_demo" destination looks like this:
public void initializeDestinations()
{
String destinationId = "fleet_demo";
String serviceId = "message-service";
MessageBroker broker = MessageBroker.getMessageBroker(null);
MessageService service = (MessageService)
broker.getService(serviceId);
MessageDestination destination = (MessageDestination)
service.createDestination(destinationId);
destination.addChannel("my-streaming-amf");
destination.addChannel("my-polling-amf");
ServerSettings serverSettings = new ServerSettings();
serverSettings.setMaxCacheSize(1000);
serverSettings.setMessageTTL(0);
serverSettings.setDurable(false);
destination.setServerSettings(serverSettings);
if (service.isStarted())
{
//initialize and run the destination
destination.start();
}
}
The bootstrapper also spawns a separate thread that continuously
receives location data from our server and packages it into an
AsyncMessage and routes it to the appropriate destination using a
method similar to this:
private void sendMessage(latitudeFromServer:double,
longitudeFromServer:double)
{
MessageBroker msgBroker = MessageBroker.getMessageBroker(null);
String clientID = UUIDUtils.createUUID(false);
AsyncMessage msg = new AsyncMessage();
msg.setDestination("fleet_demo");
msg.setHeader("latitude", latitudeFromServer);
msg.setHeader("longitude", longitudeFromServer);
msg.setClientId(clientID);
msg.setMessageId(UUIDUtils.createUUID(false));
msg.setTimestamp(System.currentTimeMillis());
msgBroker.routeMessageToService(msg, null);
}
Now I start up the server and the bootstrapper initializes the
"fleet_demo" endpoint and the sendMessage thread routes location data
perfectly to my flex client(averaging about 500-1600 messages per
hour) It works! This keeps up for about 5-6 days. After that I stop
receiving any messages when I should be. Its as though the
MessageBrokerServlet just goes silent. The only way to fix this is to
restart jboss and when I try to shutdown the server I get this NPE
message from the MessageBrokerServlet:
11:22:36,295 INFO [Server] Runtime shutdown hook called, forceHalt: true
11:22:36,295 INFO [Server] JBoss SHUTDOWN: Undeploying all packages
11:22:36,296 INFO [TomcatDeployer] undeploy, ctxPath=/jmx-console,
warUrl=.../deploy/jmx-console.war/
11:22:36,330 INFO [TomcatDeployer] undeploy, ctxPath=/enterprise,
warUrl=.../deploy/enterprise.war/
11:22:36,331 INFO [StandardWrapper] Waiting for 5 instance(s) to be
deallocated
11:22:37,350 INFO [StandardWrapper] Waiting for 5 instance(s) to be
deallocated
11:22:38,373 INFO [StandardWrapper] Waiting for 3 instance(s) to be
deallocated
11:22:38,512 ERROR [[MessageBrokerServlet]] Servlet.service() for
servlet MessageBrokerServlet threw exception
java.lang.NullPointerException
at
flex.messaging.endpoints.BaseStreamingHTTPEndpoint.handleFlexClientStreamingOpenRequest(BaseStreamingHTTPEndpoint.java:959)
at
flex.messaging.endpoints.BaseStreamingHTTPEndpoint.serviceStreamingRequest(BaseStreamingHTTPEndpoint.java:1131)
at
flex.messaging.endpoints.BaseStreamingHTTPEndpoint.service(BaseStreamingHTTPEndpoint.java:468)
at
flex.messaging.MessageBrokerServlet.service(MessageBrokerServlet.java:377)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at
org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
at
org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at
org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
at java.lang.Thread.run(Thread.java:595)
11:22:38,514 ERROR [[MessageBrokerServlet]] Servlet.service() for
servlet MessageBrokerServlet threw exception
java.lang.NullPointerException
at
flex.messaging.endpoints.BaseStreamingHTTPEndpoint.handleFlexClientStreamingOpenRequest(BaseStreamingHTTPEndpoint.java:959)
at
flex.messaging.endpoints.BaseStreamingHTTPEndpoint.serviceStreamingRequest(BaseStreamingHTTPEndpoint.java:1131)
at
flex.messaging.endpoints.BaseStreamingHTTPEndpoint.service(BaseStreamingHTTPEndpoint.java:468)
at
flex.messaging.MessageBrokerServlet.service(MessageBrokerServlet.java:377)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at
org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
at
org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at
org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
at java.lang.Thread.run(Thread.java:595)
I've created a bug report at the Adobe BlazeDS bug and issue
management page but I need a robust messaging solution for this
project and I was wondering if anybody here had any experience
regarding this problem.
Thanks for reading,
-Justin
