My take is a little different, instead services are discovered and registered, then the client can utilise them.
The approach you're now suggesting is exactly what Bharath has implented, this is a great first effort and I believe it can be improved. It's only worked since River 3.0, I think we can do much more to support OSGi. Regards, Peter. Sent from my Samsung device. Include original message ---- Original message ---- From: Michał Kłeczek <michal@kleczekorg> Sent: 14/02/2017 01:05:54 am To: dev@river.apache.org Subject: Re: OSGi NP Complete Was: OSGi - deserialization remote invocation strategy There are actually two things that we are discussing at the same time: 1. The need to have an "installer" object and how it should be provided to the client 2. The algorithm of class loader resolution in OSGi These two things are orthogonal to each other and your question is about point 2. My take on this is that in OSGi you have to delay the unmarshalling decision until a client bundle asks for a service. Then you simply create a proxy ClassLoader with the delegation parent set to the requesting bundle ClassLoader. It means that many instances of the service proxy might be present in the client environment - but that is fine since it is no different than deserializing the service proxy in two JVMs. Thanks, Michal Peter wrote: > service providers for each api version can still be loaded. > > But I don't see a way to force all clients to use a single service api >version without a compatibility layer. Why not just reload the clients so >they can use the latest compatible version of a service? > > How does your proposed solution solve this problem? > > Regards, > > Peter. > > Sent from my Samsung device > > Include original message > ---- Original message ---- > From: Michał Kłeczek<mic...@kleczek.org> > Sent: 14/02/2017 12:39:40 am > To: dev@river.apache.org > Subject: Re: OSGi NP Complete Was: OSGi - deserialization remote invocation >strategy > > But what if the client has MULTIPLE clients - each with its own exact > API version? > > OSGi handles this case just fine with service trackers. > > Do you want to give up on this? > > Thanks, > Michal > > Peter wrote: >> You can however for each service api package version, it's all in the >>smart proxy bundle manifest. >> >> You are bound by the dependency resolution process, the client can only >>choose from compatible versions. The service has the power to constrain its >>proxy bundle manifest if it wishes. >> >> Regards, >> >> Peter. >> >> Sent from my Samsung device >> >> Include original message >> ---- Original message ---- >> From: Michał Kłeczek<mic...@kleczek.org> >> Sent: 14/02/2017 12:24:58 am >> To: dev@river.apache.org >> Subject: Re: OSGi NP Complete Was: OSGi - deserialization remote >>invocation strategy >> >> >> Peter wrote: >>> There a multiple remote services, if one client cant obtain a service >>>because there is also a later version installed then you need a service that >>>doesn't import the later version. You can still supply another service to >>>cater. >> This does not scale because you would have to have one service per each >> service interface version any client might require. >> >> No... You have to be able to make this class resolution decision on the >> client. >> And if the client VM allows to have many class loading context at the >> same time (as is the case with OSGI) then >> the infrastructure has to take care of this resolution. >> >> But you cannot force the service provider to provide separate instance >> for each case. >> >> Thanks, >> Michal >> >> > > >
