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Posted to users@cxf.apache.org by Benson Margulies <bi...@gmail.com> on 2010/09/30 16:15:22 UTC

JMS pub/sub, JAX-WS, async, and where are those replies going anyway?

I'm trying to perform a mental mapping from what I know about SOAP to
what I know about JMS. Which, in the later case, is not as much as it
might be.

In a JMS-y sort of model, 'thing a' pushes a unit of work onto a
queue, and there are a school of (b) sharks looking for something to
do.

One of them gets the unit of work and works on it.

If the WebMethod is *not* OneWay, then presumably the (a) thing is
blocked waiting for one of the (b) things to respond? And the response
travels back through some other JMS queue that (ahem) springs into
existence as part of the client proxy setup? Or does JMS have a
response channel as a basic mechanism? Or is @OneWay required for
pub/sub?

Does the JAX-WS asyncronous business with the Futures work with JMS
when there is some sort of reply?

Re: JMS pub/sub, JAX-WS, async, and where are those replies going anyway?

Posted by Daniel Kulp <dk...@apache.org>.

On Thursday 30 September 2010 10:15:22 am Benson Margulies wrote:
> I'm trying to perform a mental mapping from what I know about SOAP to
> what I know about JMS. Which, in the later case, is not as much as it
> might be.
> 
> In a JMS-y sort of model, 'thing a' pushes a unit of work onto a
> queue, and there are a school of (b) sharks looking for something to
> do.
> 
> One of them gets the unit of work and works on it.
> 
> If the WebMethod is *not* OneWay, then presumably the (a) thing is
> blocked waiting for one of the (b) things to respond?

Yep.  It's a bit different on 2.3 than on <=2.2.x.  In 2.3, we actually use 
the the spring call to jmsTemplate.receiveSelected to retrieve the response 
immediately in the conduit.  With 2.2.x, it would unwind the stack and wait up 
in the client for a response to eventually arrive elsewhere.   In either case, 
it's waiting. (providing you don't use the async API's)

> And the response
> travels back through some other JMS queue that (ahem) springs into
> existence as part of the client proxy setup? Or does JMS have a
> response channel as a basic mechanism? Or is @OneWay required for
> pub/sub?

We support a bunch of ways of handling this.   I think the default is to 
create a temporary queue for the responses to travel on.  However, we also 
support using a predefined and shared queue, but using a message selector to 
select off the message that is appropriate.   It really depends on how your 
infrastructure is setup and what's easier for you to manage.

> Does the JAX-WS asyncronous business with the Futures work with JMS
> when there is some sort of reply?

Yes.  When it's not a sync call, the JMSListener will be setup and everything 
will unwind.   As responses come in, they will get coorelated and the 
appropriate callback/future handled.   You can have 1000 requests  outstanding 
and just the thread or two for the JMSLIstener will be created.

-- 
Daniel Kulp
dkulp@apache.org
http://dankulp.com/blog

AW: JMS pub/sub, JAX-WS, async, and where are those replies going anyway?

Posted by Schneider Christian <Ch...@enbw.com>.

Hi Benson,

if you have several consumers and want only one to react then pub/sub (topics) is not the right solution. In your case you simply use one queue that all consumers listen on. In jms normally the jms server will send to the present consumers using some round robin scheme (or other depending on jms server). In any case the server makes sure only one consumer will get the message.

Then the consumer will do his work and send a reply back to the destination named in the JMSReplyTo header. So where the reply goes depends on the sender. The sender has to set up a reply queue and set it in the message.

Stacks like cxf and camel provide support for request response scenarios like above. There are two common ways for the reply queue. You can use a fixed queue or you can use a temporary queue. If you configure no reply queue in CXF then a temporary queue will be used.

Another thing is the correlation of sent and received messages. This can hit you if you talk with a non cxf stack but in CXF to CXF scenarios you do not have to care about it.

A config like below should get you going for the client side. The server will be configured similarly.

Best Regards

Christian

-----------------

	<client id="service" xmlns="http://cxf.apache.org/jaxws"
		serviceClass="the java interface for the service" address="jms://">
		<features>
            <bean class="org.apache.cxf.transport.jms.JMSConfigFeature" xmlns="http://www.springframework.org/schema/beans" >
              <property name="jmsConfig" ref="jmsConfig"/>
            </bean>
			<logging xmlns="http://cxf.apache.org/core" />
		</features>
	</client>
	<bean id="jmsConfig" class="org.apache.cxf.transport.jms.JMSConfiguration"
	   p:autoResolveDestination="true" 
	   p:connectionFactory-ref="jmsConnectionFactory"
	   p:targetDestination="testqueue" />
	<bean id="jmsConnectionFactory" class="com.tibco.tibjms.TibjmsConnectionFactory">
		<property name="serverUrl" value="${jms.serverUrl}" />
		<property name="userName" value="${jms.userName}" />
		<property name="userPassword" value="${jms.userPassword}" />
		<property name="reconnAttemptCount" value="${jms.reconnAttemptCount}" />
		<property name="reconnAttemptDelay" value="${jms.reconnAttemptDelay}" />
	</bean>
-------------------



Christian Schneider
Informationsverarbeitung 
Business Solutions
Handel und Dispatching

Tel : +49-(0)721-63-15482

EnBW Systeme Infrastruktur Support GmbH
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Geschäftsführer: Jochen Adenau, Hans-Günther Meier


-----Ursprüngliche Nachricht-----
Von: Benson Margulies [mailto:bimargulies@gmail.com] 
Gesendet: Donnerstag, 30. September 2010 16:15
An: CXF Users
Betreff: JMS pub/sub, JAX-WS, async, and where are those replies going anyway?

I'm trying to perform a mental mapping from what I know about SOAP to
what I know about JMS. Which, in the later case, is not as much as it
might be.

In a JMS-y sort of model, 'thing a' pushes a unit of work onto a
queue, and there are a school of (b) sharks looking for something to
do.

One of them gets the unit of work and works on it.

If the WebMethod is *not* OneWay, then presumably the (a) thing is
blocked waiting for one of the (b) things to respond? And the response
travels back through some other JMS queue that (ahem) springs into
existence as part of the client proxy setup? Or does JMS have a
response channel as a basic mechanism? Or is @OneWay required for
pub/sub?

Does the JAX-WS asyncronous business with the Futures work with JMS
when there is some sort of reply?