[news.eclipse.technology.riena] Re: Release 1.0.0.M1

[Scott Lewis <slewis@xxxxxxxxxxxxx>]

Hi Christian,

Congrats to the team on the M1.

I have some technical questions about the getting started examples and 
about Riena in general.

1) In your getting started under "Accessing the remote OSGi Service" you 
have:

		pingPongReg = rsf.createAndRegisterProxy(IPingPong.class, url, protocol);

And in the plugin 
org.eclipse.riena.communication.sample.pingpong.client.config (which 
seems to be the source):

		pingPongReg = rsf.createAndRegisterProxy(serviceInterface, url, 
protocol, "de.compeople.pingpong.config");

1) What is this fourth parameter?

2) A thought:  wouldn't it be a cleaner/simpler/less error prone to have 
the 'createAndRegisterProxy' call combine the url and protocol Strings 
into some sort of 'IEndpoint' object that includes both info about the 
wire protocol (e.g. http), and info about the service publisher-level 
protocol (hessian in this case)?

One possibility for doing this would be to create a new ECF namespace 
extension (i.e. a 'riena' namespace), which would allow you to do things 
like uniqueness checking on construction, create your own factory for 
your type of IEndpoint, etc.

3) What if the client doesn't have this endpoint information in advance? 
 I assume that that's where any discovery mechanisms come in, correct?

I don't know anything/much about Hessian, but

4) I assume that the actual http request/response is made at service 
invocation time, correct?

5) Does it have any connection caching/etc to improve performance?

6) What about multiple simultaneous thread access to a given service 
method?  How is this handled?

7) If someone wanted to replace hessian with a connection-oriented 
middleware (e.g. JMS, private protocol, etc), would they be able to do 
this without modifying riena itself?

8) Are there any ways to specify timeouts associated with remote 
invocations (other than setting the JRE-wide http connect and read 
timeouts)?

OK, I see that some of the real remote service invocation action is in 
HessianProxy.invoke/3.  This seems to be where the actual connection is 
created, the parameters marshalled, the http request/response handled, 
and a result returned.

I think it will be straightforward to create an Riena-based provider for 
the ECF remote services API...I'll be starting on this soon.

Hopefully some more questions as we go.

Thanks,

Scott