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From Minto van der Sluis <>
Subject Re: No TcManager instance available
Date Tue, 08 Apr 2014 19:55:01 GMT
Reto Gmür schreef op 8-4-2014 18:20:
> Hi Minto
>> Clearly the static method should not be used.
>>> Well, it seems you don't have an a active TcManager the most likely cause
>>> given the zz-885 change is that you don't have a TcProvider marked as
>>> general purpose. It should be easy to mark your TcProvider as
>>> general-purpose, but we can also discuss zz-885, maybe it was a bad idea.
>> Personally I fail to see the benefit. If there is no TcProvider there
>> will also not be a general-purpose provider. So the behaviour is
>> probably still the same as before. In my opinion it does not solve the
>> issue you had in the first place.
> It prevent the problem that a TcManager is available even if not TcProvider
> is able to create new graphs. In our traditional launcher this is addressed
> with startlevels but I don't think that this is a good solution.
Ah now I see.

Why couldn't TcManager just report errors/exceptions when no suitable
TcProvider is present? It's a manager after all. Why should the manager
disappear when there is nothing to manage? 

Why are start levels not a good solution. It's this just the kind of
scenario they were designed for? Just start the components that use
TcManager in a later startlevel than TcManager (and TcProviders). This
is how I do it inside Apache Karaf. TcManager and TcProviders are the
infrastructure my app uses, so I start the infrastructure first before
starting my app.
> A problem that is still open is what if there is an in-memory TcProvider in
> the system? I've had problems that graphs got created in this because the
> TdbTcProvider was loaded later.
> Ideally TcManager should wait for all TcProviders to be active, but I'm not
> sure if an d how this can be done.
How is TcManager to know which TcProvider to expect to be able to know
whether they are all active? Besides OSGi is a dynamic environment.
Shouldn't TcManager be able to cope with this dynamic behaviour?
Theoretically TcProviders could come and go.
> Cheers,
> Reto
>>> Cheers,
>>> Reto
>> Fortunately I was able to resolve my issue. Thanks for that.
>> I also have some other issue/things to discuss, but I will use a
>> separate thread for that.
>> Regards,
>> Minto
>> --
>> ir. ing. Minto van der Sluis
>> Software innovator / renovator
>> Xup BV
>> Mobiel: +31 (0) 626 014541

ir. ing. Minto van der Sluis
Software innovator / renovator
Xup BV

Mobiel: +31 (0) 626 014541

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