[rabbitmq-discuss] NPE in RpcClient

Neil Ellis neil.ellis at mangala.co.uk
Sat Mar 15 16:22:19 GMT 2008

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  

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  

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  

Anyway let us know - I'm on Skype most of the time - I think you have  
me as a contact (neilellis).

All the best

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)

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 2431 bytes
Desc: not available
Url : http://lists.rabbitmq.com/pipermail/rabbitmq-discuss/attachments/20080315/be34eb60/attachment.bin 

More information about the rabbitmq-discuss mailing list