[rabbitmq-discuss] Newton + Mule + RabbitMQ --- (Was: NPE in RpcClient)
Alexis Richardson
alexis.richardson at cohesiveft.com
Fri Apr 4 11:56:34 BST 2008
Neil,
Please could I post the link for your Newton-Mule-RabbitMQ demo to the
list, plus a description of how to use it?
Everyone,
We were able to fix a lot of the issues in the RpcClient discussion
below. For Mule users, please see the Mule Forge for any patches.
Neil has done a really cool demo that uses Newton to set up a bunch of
Mules and Rabbits performing a distributed workflow, which in the demo
is a news feed and image processor for a notional news aggregator.
alexis
On Sun, Mar 16, 2008 at 1:43 AM, Neil Ellis <neil.ellis at mangala.co.uk> wrote:
>
>
> 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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>
>
--
Alexis Richardson
+44 20 7617 7339 (UK)
+44 77 9865 2911 (cell)
+1 650 206 2517 (US)
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