activemq-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jason Dillon <ja...@planet57.com>
Subject Re: Having problem with EventListener remoting (w/Lingo)
Date Fri, 03 Nov 2006 03:48:02 GMT
Hrm... I played around with this more... and I found that using a  
topic, that if I comment the listener.pong() that everything works, w/ 
o exceptions.

I also read over this article:

     http://jroller.com/page/sjivan? 
entry=asynchronous_calls_and_callbacks_using

Which was very good, and I played with the example... which appears  
to be working too.

So, maybe the problem is the async invoke which is carrying the  
callback object is not getting registered properly?  Or maybe its not  
possible to use callbacks from async invocations?

I also noticed that in the example, it uses "remoteInvocationFactory"  
instead of "metadataStratagy" on the bean proxy:

     <bean id="invocationFactory"  
class="org.logicblaze.lingo.LingoRemoteInvocationFactory">
         <constructor-arg>
             <bean class="org.logicblaze.lingo.SimpleMetadataStrategy">
                 <!-- enable async one ways -->
                 <constructor-arg value="true"/>
             </bean>
         </constructor-arg>
     </bean>

What is the difference?

Are callback objects not allowed to be used in the same context of an  
invocation?  I tried spinning off a new thread to invoke listener.pong 
(), but it produced the same "destination must be specified" problem,  
but with a shorter trace:

<snip>
Exception in thread "Thread-4"  
java.lang.UnsupportedOperationException: A destination must be  
specified.
         at org.apache.activemq.ActiveMQMessageProducer.send 
(ActiveMQMessageProducer.java:448)
         at org.logicblaze.lingo.jms.impl.OneWayRequestor.doSend 
(OneWayRequestor.java:196)
         at org.logicblaze.lingo.jms.impl.MultiplexingRequestor.doSend 
(MultiplexingRequestor.java:189)
         at org.logicblaze.lingo.jms.impl.OneWayRequestor.send 
(OneWayRequestor.java:101)
         at org.logicblaze.lingo.jms.impl.OneWayRequestor.send 
(OneWayRequestor.java:97)
         at  
org.logicblaze.lingo.jms.impl.MultiplexingRequestor.request 
(MultiplexingRequestor.java:122)
         at org.logicblaze.lingo.jms.JmsClientInterceptor.invoke 
(JmsClientInterceptor.java:138)
         at  
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed 
(ReflectiveMethodInvocation.java:185)
         at  
org.springframework.aop.framework.JdkDynamicAopProxy.invoke 
(JdkDynamicAopProxy.java:209)
         at $Proxy6.pong(Unknown Source)
         at org.apache.geronimo.gbuild.ping.PingResponderImpl$1.run 
(PingResponderImpl.java:49)
</snip>

I'd really like to get callbacks working from async invocations, as  
it makes a lot of sense when dealing with an unknown number of remote  
nodes where some transient processing needs to be done.  The only  
other way I can think of to do the same thing would be to create  
services, proxies and destinations for the responses... which will  
get out of hand quite easily and may have other issues with  
synchronizing up with the correct originating client that initiated  
the messages.

So... I think callbacks using temporary destinations is really  
ideal.  But how do I tell a bunch of nodes to do something and pass  
them a callback from a single invoke?

--jason


On Nov 2, 2006, at 3:57 PM, Jason Dillon wrote:

> Hi folks, I am trying to figure out some of the more advanced Lingo  
> usage... trying to get a simple working example of EventListener  
> remoting, but so far I have had no luck.
>
> I'm trying to get a super-simple ping/pong from a client to a set  
> of nodes listening on a topic, where the invocation is one-way, and  
> the server's ping responder will invoke a method on an ping  
> listener to send its pong.
>
> This is what I've got:
>
> <snip>
> public interface PingListener
>     extends EventListener
> {
>     void pong();
> }
>
> public interface PingResponder
> {
>     void ping(PingListener listener);
> }
>
> public class PingResponderImpl
>     implements PingResponder
> {
>     public void ping(final PingListener listener) {
>         log.info("Responding to PING")
>         listener.pong();
>     }
> }
> </snip>
>
> My client is also simple, though in this example I've trimmed out  
> the bits which load the spring ctx and autowire the components:
>
> <snip>
> public class PingClient
> {
>     public void ping() {
>         PingCollector collector = new PingCollector();
>         responder.ping(collector);
>         // wait for ctrl-c to end
>     }
>
>     public class PingCollector
>         implements PingListener
>     {
>         public void pong() {
>             log.info("Received PONG");
>         }
>     }
> }
> </snip>
>
> And then the spring ctx:
>
> <snip>
> <beans xmlns="http://www.springframework.org/schema/beans"
>        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>        xsi:schemaLocation="http://www.springframework.org/schema/ 
> beans http://www.springframework.org/schema/beans/spring- 
> beans-2.0.xsd">
>
>     <bean id="jmsFactory"  
> class="org.apache.activemq.ActiveMQConnectionFactory"  
> scope="singleton">
>         <property name="brokerURL" value="vm://localhost? 
> broker.persistent=false"/>
>     </bean>
>
>     <bean id="pingResponderDestination"  
> class="org.apache.activemq.command.ActiveMQTopic" scope="singleton">
>         <constructor-arg index="0" value="gbuild.pingResponder"/>
>     </bean>
>
>     <bean id="pingResponder"  
> class="org.logicblaze.lingo.jms.JmsProxyFactoryBean">
>         <property name="serviceInterface"  
> value="org.apache.geronimo.gbuild.ping.PingResponder"/>
>         <property name="connectionFactory" ref="jmsFactory"/>
>         <property name="destination" ref="pingResponderDestination"/>
>     </bean>
>
>     <bean id="pingReponderImpl"  
> class="org.apache.geronimo.gbuild.ping.PingResponderImpl"  
> scope="singleton"/>
>
>     <bean id="pingReponderService"  
> class="org.logicblaze.lingo.jms.JmsServiceExporter" scope="singleton">
>         <property name="service" ref="pingReponderImpl"/>
>         <property name="serviceInterface"  
> value="org.apache.geronimo.gbuild.ping.PingResponder"/>
>         <property name="connectionFactory" ref="jmsFactory"/>
>         <property name="destination" ref="pingResponderDestination"/>
>     </bean>
> </beans>
> </snip>
>
> In this configuration, I see the "Responding to PING" and "Received  
> PONG" log messages, which is followed by some exceptions after a  
> delay:
>
> <snip>
> 15:39:43,075 WARN  [JmsClientInterceptor] Remote access error:  
> invocation: method 'pong', arguments []; target is null
> javax.jms.JMSException:  
> edu.emory.mathcs.backport.java.util.concurrent.TimeoutException
>         at  
> org.logicblaze.lingo.jms.impl.MultiplexingRequestor.createJMSException 
> (MultiplexingRequestor.java:205)
>         at  
> org.logicblaze.lingo.jms.impl.MultiplexingRequestor.request 
> (MultiplexingRequestor.java:133)
>         at org.logicblaze.lingo.jms.JmsClientInterceptor.invoke 
> (JmsClientInterceptor.java:138)
>         at  
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed 
> (ReflectiveMethodInvocation.java:185)
>         at  
> org.springframework.aop.framework.JdkDynamicAopProxy.invoke 
> (JdkDynamicAopProxy.java:209)
>         at $Proxy6.pong(Unknown Source)
> ...
> </snip>
>
> And then a warning from the MultiplexingRequestor:
>
> <snip>
> 15:39:43,113 WARN  [MultiplexingRequestor] Response received for  
> unknown correlationID: 2 request: ActiveMQObjectMessage {commandId  
> = 9, responseRequired = true, messageId =  
> ID:Bliss.local-52836-1162510752209-2:6:1:1:2, originalDestination =  
> null, originalTransactionId = null, producerId =  
> ID:Bliss.local-52836-1162510752209-2:6:1:1, destination = temp- 
> queue://ID:Bliss.local-52836-1162510752209-2:13:1, transactionId =  
> null, expiration = 1162510813098, timestamp = 1162510783104,  
> arrival = 0, correlationId = 2, replyTo = null, persistent = true,  
> type = null, priority = 4, groupID = null, groupSequence = 0,  
> targetConsumerId = null, compressed = false, userID = null, content  
> = org.apache.activemq.util.ByteSequence@10e392,  
> marshalledProperties = null, dataStructure = null,  
> redeliveryCounter = 0, size = 12390, properties = null,  
> readOnlyProperties = true, readOnlyBody = true, droppable = false}
> </snip>
>
> And at this point, the method call to responder.ping() is still  
> blocking.
>
> If I change the destination to use a queue, then I get the same  
> timeout trace, but the call to responder.ping() unblocks due to the  
> JMSException being propagated.
>
> If I enable a metadata strategy to make this async for one way  
> voids, with something like:
>
> <snip>
>     <bean id="pingResponder"  
> class="org.logicblaze.lingo.jms.JmsProxyFactoryBean">
>         <property name="serviceInterface"  
> value="org.apache.geronimo.gbuild.ping.PingResponder"/>
>         <property name="connectionFactory" ref="jmsFactory"/>
>         <property name="destination" ref="pingResponderDestination"/>
>         <property name="metadataStrategy">
>             <bean class="org.logicblaze.lingo.SimpleMetadataStrategy">
>                 <constructor-arg value="true"/>
>             </bean>
>         </property>
>     </bean>
> </snip>
>
> The I see the "Responding to PING" but right after I get this  
> exception:
>
> <snip>
> 15:46:35,401 WARN  [RemoteInvocationTraceInterceptor] Processing of  
> JmsServiceExporter remote call resulted in fatal exception:  
> org.apache.geronimo.gbuild.ping.PingResponder.ping
> java.lang.UnsupportedOperationException: A destination must be  
> specified.
>         at org.apache.activemq.ActiveMQMessageProducer.send 
> (ActiveMQMessageProducer.java:448)
>         at org.logicblaze.lingo.jms.impl.OneWayRequestor.doSend 
> (OneWayRequestor.java:196)
>         at  
> org.logicblaze.lingo.jms.impl.MultiplexingRequestor.doSend 
> (MultiplexingRequestor.java:189)
>         at org.logicblaze.lingo.jms.impl.OneWayRequestor.send 
> (OneWayRequestor.java:101)
>         at org.logicblaze.lingo.jms.impl.OneWayRequestor.send 
> (OneWayRequestor.java:97)
>         at  
> org.logicblaze.lingo.jms.impl.MultiplexingRequestor.request 
> (MultiplexingRequestor.java:122)
>         at org.logicblaze.lingo.jms.JmsClientInterceptor.invoke 
> (JmsClientInterceptor.java:138)
>         at  
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed 
> (ReflectiveMethodInvocation.java:185)
>         at  
> org.springframework.aop.framework.JdkDynamicAopProxy.invoke 
> (JdkDynamicAopProxy.java:209)
>         at $Proxy6.pong(Unknown Source)
> ...
> </snip>
>
> I am using Apple's JDK 1.5, Lingo 1.3 and Spring 2.0.  Other simple  
> sync invocations work fine... but I really need to get something  
> working for more complicated invocations to and from an arbitrary  
> set of nodes.
>
> Does anyone have any ideas how to get this working?  I have been  
> digging around in the lingo svn, looking at the tests.  Looks like  
> there is a test that uses an EventListener... and it appears to  
> pass, but I don't know what I am doing differently.
>
> I've also been looking for other input on the lingo nabble  
> forums... but so far... no luck.
>
> Any help is appreciated.
>
> Thanks,
>
> --jason


Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message