Re: [ecf-dev] Problem using multiple services from single server

[Scott Lewis <slewis@xxxxxxxxxxxxx>]

On 3/12/2015 8:41 AM, Peter Hermsdorf wrote:

Hi Wim,

I'll take a closer look at that - maybe I can somehow relax the service dependencies on startup

I now (again) have the problem that my edef registration/description bundles are not honoured. This time in the integration Testsuite.
When running the testsuite with -console -noExit i see:
> ss edef
194    ACTIVE      com.godyo.IService1.edef_1.0.0
195    ACTIVE      com.godyo.IService2.edef_1.0.0

but the services do not get bound. When refreshing the bundles the binding is triggered immediately.

Any ideas how to fix that?

I'm still catching up with the emails this morning, and Wim just responded to this question with some info on DS startup sequence.  I do also suspect start ordering and/or the problem I mentioned before...it seems that Equinox/framework restarts don't end up triggering edef bundles detection/reading (via BundleTracker).  There could be several explanations for this...e.g. start level/start order (Wim's point), and it could relate to some framework subtlety about starting of bundles without activator (which I assume your edef bundles don't have an activator as they usually do not).

One thing that occurred to me:  are you using the 'eclipse lazy start of bundles' approach or the 'osgi server eager start of bundles' approach (I'm mostly interested in consumer-side, since that is where you seem to be having difficulties getting things done in the right order.

What would be another "easy" approach to trigger the import? Is there some code that i can use to configure the EndpointDescriptions programmatically?

The answer to this is a definite 'yes' :). 

One way:  have piece of code that explicitly starts (and first stops, if necessary) the edef bundles.  If this is in an activator then at least you can determine exactly *when* it's run, or it can/could be triggered via some UI event (e.g. menu selection/whatever).

Second way:   The RSA spec defines a service:  org.osgi.service.remoteserviceadmin.RemoteServiceAdmin that allows programmatic control of the importing of a service.  Specifically the method RemoteServiceAdmin.importService(EndpointDescription).   If you like, you can/could simply create an ecf EndpointDescription by passing in a Map of properties, and call RemoteServiceAdmin.importService with your EndpointDescription.

A third way:  Create and use your own TopologyManager.  The RSA spec defines a role called the 'topology manager' that does the above import (and export actually).  ECF's default topology manager is the BasicTopologyManager in the org.eclipse.ecf.osgi.distribution bundle.  The TopologyManager defines the link between endpoint description discovery and calling RemoteServiceAdmin.importService.

There are actually additional ECF-specific ways to programmatically get the discovery + import to happen...but customizing/overriding one of the ECF-specific services that implement the RSA specification (i.e. interfaces in org.eclipse.ecf.osgi.service.remoteserviceadmin package).   I'm happy to discuss and describe these methods, but before I take that step it would probably be better to explore/discuss/exhaust the 3 methods described above.

Scott