[rabbitmq-discuss] NPE in RpcClient

Neil Ellis neil.ellis at mangala.co.uk
Sun Mar 16 00:43:28 GMT 2008



The mule configs are:


------

   <mule-descriptor name="Poller"  
implementation="org.mule.components.simple.BridgeComponent">

             <inbound-router>
                 <endpoint address="http://newsrss.bbc.co.uk/rss/newsonline_uk_edition/front_page/rss.xml 
"
                           connector="pollingHttp">
                     <properties>
                         <property name="pollingFrequency"  
value="10000"/>
                     </properties>
                 </endpoint>
             </inbound-router>

             <outbound-router>
                 <router  
className="org.mule.routing.outbound.FilteringXmlMessageSplitter">
                     <endpoint address="amqp://news:fanout/?routing_key=news 
" synchronous="false" transformers="DOM2String">
                         <filter expectedType="org.dom4j.Document"
                                  
className="org.mule.routing.filters.PayloadTypeFilter"/>
                     </endpoint>
                     <reply-to address="amqp://result:fanout/? 
routing_key=result"/>
                     <properties>
                         <property name="splitExpression" value="/rss/ 
channel/item"/>
                         <property name="validateSchema" value="false"/>
                     </properties>
                 </router>
             </outbound-router>

         </mule-descriptor>

-----

         <mule-descriptor name="Worker"  
implementation="org.mule.components.simple.PassThroughComponent">
             <inbound-router>
                 <endpoint address="amqp://news:fanout/?queue=news"   
transformers="RSSToHeadline" synchronous="false" />
             </inbound-router>
         </mule-descriptor>

-----

         <mule-descriptor name="SimpleReceiver"  
implementation="org.mule.components.simple.EchoComponent">
             <inbound-router>
                 <endpoint address="amqp://result:fanout/? 
queue=result"/>
             </inbound-router>
             <outbound-router>
                 <router  
className="org.mule.routing.outbound.OutboundPassThroughRouter">
                     <endpoint address="stream://System.out"/>
                 </router>
             </outbound-router>
         </mule-descriptor>

----


The above are on 3 different instances of Mule on the same physical  
machine, the RabbitMQ server is running on a seperate VM. The  
exception is below:

 > [03-16 00:37:00] ERROR DefaultExceptionStrategy  
[RabbitMQ.dispatcher.15]: Caught exception in Exception Strategy:  
Socket closed
java.net.SocketException: Socket closed
	at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:99)
	at java.net.SocketOutputStream.write(SocketOutputStream.java:115)
	at java.io.DataOutputStream.writeByte(DataOutputStream.java:136)
	at com.rabbitmq.client.impl.Frame.writeTo(Frame.java:189)
	at  
com 
.rabbitmq 
.client.impl.SocketFrameHandler.writeFrame(SocketFrameHandler.java:146)
	at  
com.rabbitmq.client.impl.AMQConnection.writeFrame(AMQConnection.java: 
295)
	at com.rabbitmq.client.impl.AMQCommand.transmit(AMQCommand.java:175)
	at com.rabbitmq.client.impl.ChannelN.basicPublish(ChannelN.java:370)
	at com.rabbitmq.client.impl.ChannelN.basicPublish(ChannelN.java:351)
	at com.rabbitmq.client.RpcClient.publish(RpcClient.java:163)
	at  
com 
.rabbitmq 
.mule.transport.RabbitDispatcher.doDispatch(RabbitDispatcher.java:78)

I'm taking another look at the code right now to see if I can figure  
out what's going wrong.

Kind regards
Neil
On 15 Mar 2008, at 18:42, Ross Mason wrote:

> Hi Neil,
>
> This does sound interesting.  There is still a fair way to go on the
> Mule Rabbit Transport, but there are some simple use cases that work.
> What is the problem you have with A -> B -> C? is it that the message
> doesn't get to C? If so, Are you trying to perform an RPC call from A?
> (i.e.  RPC from A to get a response from C via B).
>
> BTW Guys, I would like to do a Beta release of the Rabbit Connector
> before MuleCon, but right now I snowed under this weekend.
>
> Cheers,
>
> Ross Mason
> CTO, Co-Founder
> MuleSource Inc.
>
> http://mulesource.com | http://blog.rossmason.com
>
>
> On 15 Mar 2008, at 17:22, Neil Ellis wrote:
>
>> Hi Alexis
>>
>> No probs.
>>
>> Alas I don't have the budget for jet-setting :-(
>>
>> I've been having problems with getting the Mule connector to handle
>> A->B->C messages although A->B seems okay. If anyone from the
>> RabbitMQ side could give me a little hand on getting it up and
>> running that would be fabulous - I'm pretty busy at the moment
>> between this work and project:Einstein/deesel ( http://einstein.codecauldron.org
>> / http://deesel.codecauldron.org ) so any help would increase the
>> chances of having a demo ready for you.
>>
>> I've restructured the current demo to show
>>
>> 1 Polller Mule instance reading from an RSS feed.
>> 3-5 Worker Mule instances transforming the feed (at least a notional
>> idea of work).
>> 1 Displayer Mule instance displaying the transformed results to the
>> screen.
>>
>> It's a bit noddy but it shows how Newton can distribute a set of
>> Mule nodes based upon simple criteria, so on a single Newton
>> instance you would have all the Mule instances at the same time on
>> one instance, on 7 instances you would have 1 poller, 3-5 workers
>> and 1 displayer - and in between it scales appropriately. And then
>> shows RabbitMQ as the internode protocol. We could easily turn this
>> into a demo of running RabbitMQ on a large number of nodes with
>> super-easy deployment and failover in the future - that's something
>> to think about.
>>
>> We could certainly help with providing materials (i.e. slides or
>> user guide) and help getting you running the demo before hand - in
>> return would you be able to ensure that Paremus/myself get
>> appropriate credit at the demo for our part (i.e. powered by Newton
>> and the appropriate links)?
>>
>> Anyway let us know - I'm on Skype most of the time - I think you
>> have me as a contact (neilellis).
>>
>> All the best
>> Neil
>>
>>
>> On 15 Mar 2008, at 12:16, Alexis Richardson wrote:
>>
>>> Neil
>>>
>>> Thank-you very much.  That sounds like a really interesting demo.
>>> Please let us know how you get on.  Also - will you be at  
>>> MuleCon?  I
>>> am going and would love to show anything you have to folks at the
>>> conference.
>>>
>>> alexis
>>>
>>>
>>> On Thu, Mar 13, 2008 at 5:48 PM, Neil Ellis
>>> <neil.ellis at mangala.co.uk> wrote:
>>>> Hi Folks
>>>>
>>>> Not sure if this has already been reported; in version 1.2.0 of  
>>>> lib-
>>>> rabbitmq there is a NPE if the publish() method has been called on
>>>> RpcClient because the temp queue picks it up and attempts to call
>>>> setBody() on the blocker. Trivially chaning blocker.set(body) to
>>>> have
>>>> a NP check fixes this:
>>>>
>>>>                  if(blocker != null) {
>>>>                          blocker.set(body);
>>>>                   }
>>>>
>>>> This was line 150 of RpcClient. I've cc-ed the list for the mule
>>>> transport as it is the mule transport using publish() that caused  
>>>> my
>>>> problem.
>>>>
>>>> Btw. The website for the work I'm doing is http://mule4newton.codecauldron.org/mule4newton-examples/mule4newton-rabbitmq/index.html
>>>> and the src is at http://svn.codecauldron.org/mule4newton/trunk/examples/rabbitmq/
>>>> - basically we're combining Newton, Mule and RabbitMQ as an
>>>> illustration of a flexible open-source based messaging system.
>>>>
>>>> Kind regards
>>>> Neil
>>>>
>>>>
>>>> _______________________________________________
>>>> rabbitmq-discuss mailing list
>>>> rabbitmq-discuss at lists.rabbitmq.com
>>>> http://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss
>>>>
>>>>
>>>
>>>
>>>
>>> -- 
>>> Alexis Richardson
>>> +44 20 7617 7339 (UK)
>>> +44 77 9865 2911 (cell)
>>> +1 650 206 2517 (US)
>>
>
>
> _______________________________________________
> rabbitmq-discuss mailing list
> rabbitmq-discuss at lists.rabbitmq.com
> http://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss

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