some questions

[moonspring]

Hi,Eben,
How are you?

I have three questions that I have to ask,please help me.
1、do you remember the question I had asked you before about Oracle supporting?
Now I know the Shuttle ESB support the MSMQ and the SqlServer queue.I want to ask:Can I just use the MSMQ queue without SqlServer in the Pub/Sub demo?

2、I know,if I want to run the Pub/Sub,when the Pub publish a message,Where is the message?It is don't saved in database.It is in the pub Computer side,or the sub Computer side?

3、Now,Shuttle ESB can run normally in my system.But when my project go on-line,it have to keep running for 10 yes.So I want to build a clusters environment.What if the ESB pub have something wrong,I can change it to a normal one quickly. But I don't know too muck about Clusters and load balancing.Please help me.

Regards,
MoonSpring

[eben-roux]

Hi MoonSpring,

All good here thanks :) --- hope you're good too.

Shuttle does not rely on any specific technology. All the components are abstracted so you can choose the implementation type. However, the current implementations may not cover your case.

So you need an implementation of the IQueue and IQueueFactory interfaces to use a specific queue. Similarly you need an implementation of the ISubscriptionManager interface to perform pub/sub.

Currently there is no ISubscriptionManager implementation for Oracle but you are welcome to create one and send a pull request :)

I do not have Oracle experience and given my limited time I don't know when I'll be able to get to that.

As for where the message is persisted for pub/sub: it is in the relevant queue. When you publish a message all the registered subscription endpoint uris are retrieved from the ISubscriptionManager implementation. The message is then simply sent to each endpoint queue. So, depending on the queue technology, the message should end up in the destination queue.

Clustering is a whole new ball-game. You will need to give me details about what your concerns are. When something goes wrong one would need to analyze the issue and perform some corrective action. As long as a message is in an accessible all should be OK. You can always move/copy the message to another queue for processing.

I don;t quite understand what you mean by changing an endpoint to a "normal" one. There is message distribution but that is something else.

Please ask if you need further clarification.

Regards,
Eben