[rabbitmq-discuss] NPE in RpcClient

Sat Mar 15 18:42:21 GMT 2008

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)
>