On Jun 14, 2008, at 3:58 AM, Christian Schneider wrote:
Hi Daniel,
I have got an idea how I could implement several services on one
queue without too much problems.
The idea is to publish the services with a local endpoint only. Then
I configure one additional endpoint on jms and write a custom
invoker. The invoker figures out what local endpoint the request
should go to and invokes it. Then it forwards the reply back to jms.
It could find the correct endpoint either by analysing the namespace
of the xml or by using ws addressing. The only thing is I do not
know exactly how to implement this.
Is it better to do this in cxf directly or should I rather use camel
for this? The jms and invoker part sounds to me like it could be
done in camel quite nicely but I am not sure. Especially I do not
know how to do synchronous things in camel.
It definitely could be done in camel. By default, the listener on a
JMS queue is single threaded. Thus, all requests would come in on
one thread. No syncronization would be needed. You would just
take the message, figure out where to dispatch it to, and dispatch
it. It would be completely single threaded by default.
Digging into the code a bit, I notice our JMS transport does:
WorkQueueManager wqm = base.bus.getExtension(WorkQueueManager.class);
if (null != wqm) {
executor = wqm.getAutomaticWorkQueue();
}
Thus, if you put a single threaded workqueue thing on the bus, that
would accomplish it as well. The API's look like they have some
support for this already, but they aren't hooked up to anything. :-(
The simplest thing would probably be to write you own subclass/
implementation of WorkQueueManager (fairly simple) and configure that
in to the bus.
Dan
Best regards
Christian
Daniel Kulp schrieb:
On Jun 11, 2008, at 2:16 AM, Christian Schneider wrote:
Hi,
I am building webservice adapters for a legacy system. The system
can be accessed with a java api but is not multi threaded. So my
problem is
that I want to offer several services in one process and still
make sure only one service is called at a time. To make this
scalable I will then run this processes several
times on the same and different machines.
So my question is:
Can I offer several services with cxf on the same jms queue in one
process
I think so, yes. With configuration, you can use message
selectors to put multiple endpoints on the same queue and have the
messages dispatched correctly.
and make sure the whole process works only on one request at a
time and routes the reuqest to the right service?
This one I'm not sure about. Good question. CXF is definitely
designed for high scalability and mutlti-threaded cases.
Hmmmm.... One option, I guess, would be to write a custom
invoker that syncronizes things and use a single instance of that
invoker for all the endpoints. Might be harder for dynamic
deployments though.
Another option might be to write a pair of interceptors, one for
the IN chain and one for the out/out fault chains that just aquire/
release a lock of some sort.
Dan
I also would like to make management of this system as easy as
possible. Ideally I would like this process to be a kind of
application server where I can install and deinstall services
while it is running.
Still they should listen on one queue and work single threaded. I
imagined doing this with an osgi server. The problem is that
probably then each bundle will have it´s own cxf and they are not
single threaded anymore.
Any ideas for this?
Best regards
Christian
---
Daniel Kulp
[EMAIL PROTECTED]
http://www.dankulp.com/blog
---
Daniel Kulp
[EMAIL PROTECTED]
http://www.dankulp.com/blog
