Re: [ecf-dev] ServiceTracker for remote services

[Scott Lewis <slewis@xxxxxxxxxxxxxxxxx>]

Hi Eugen,

Eugen Reiswich wrote:
> Hi Scott,
>
> > Ok.  You might also look at the RFC119 support we are introducing 
> > with ECF 3.0...as it allows using ServiceTrackers for transparent 
> > remote services.  There are some tests that show this in 
> > org.eclipse.ecf.tests.osgi.services.distribution.
>
> we will switch to ECF 3.0 soon but it's not possible for now as ECF 
> 3.0 requires Eclipse 3.5. 

One possibility is that we create a version of ECF 3.0 for Eclipse 
3.4.X.  I'm not saying that we will do it, but would this help?  If so 
please join bug

https://bugs.eclipse.org/bugs/show_bug.cgi?id=263545

Note that the RFC119 impl is dependent upon Equinox 3.5 service registry 
hooks (which are not present in 3.4.X), so we actually cannot make this 
functionality available in 3.4.X.

> I just had a look at a ServiceDescovery example on 
> http://wiki.eclipse.org/Discovery_of_Remote_Services
>
> There is a lot of stuff to do before one can use the ServiceDiscovery. 
> I need to create  IServiceTypeID, Properties, URI, ServiceInfo etc and 
> I need some time to understand how they work together. Is this a 
> simple example or do I really have to create all this things? 

Yes, but as Markus indicated service properties aren't 
necessary/required.  So the entities required (on publisher) are:  URI 
(created from string), String serviceName, and IServiceTypeID (created 
from String).  These three things then go into the ServiceInfo constructor.

> I also thought about using the ECF Presence API to get the remote 
> user's IP and then switch to Riena for remote services. But I actually 
> don't like the idea of mixing different remote technologies in one 
> project.
>
> So my basic problem which I was not able to solve with ECF yet is: how 
> can I handle the dynamic of remote services in e.g. a chat application 
> where users appear and disappear very often. How can I make sure that 
> remote services are provided properly to all users independently at 
> what time a user appears? In an OSGi environtment I would use a 
> ServiceTracker to handle all dynamic, but in ECF I still don't really 
> know how to solve this problem.

I do think the RemoteServiceTracker would/will help...and the RFC119 
work will help as well.

Scott