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From Bram Pouwelse <b...@pouwelse.com>
Subject Re: Defining start level for OSGi bundles
Date Mon, 20 Oct 2014 10:17:43 GMT
Hi,

I've tried using Ace in Karaf  (think that's over a year ago by now), in my
experience the Karaf features rely on the start levels.

Regards,
Bram



2014-10-20 11:56 GMT+02:00 Marcel Offermans <marcel.offermans@luminis.nl>:

> Hello Jochen,
>
> Yes, please try that first.
>
> You might run into issues though. Karaf does not support updating
> features. If you want to "update" a feature, it will do an "uninstall" and
> "install" which is semantically very different in OSGi. It will destroy
> your bundle cache for example, which is a bad thing for bundles that
> persist data, such as ConfigurationAdmin.
>
> So I am not sure how thorough the Karaf team is in testing if "update"
> works for their bundles. I would argue that if it does not work, that is a
> bug in their bundles. :)
>
> Greetings, Marcel
>
> On 20 Oct 2014 at 10:56:01 , Walz, Jochen (ext) (
> jochen.walz@knorr-bremse.com) wrote:
>
> Thanks, Philipp, Marcel.
>
> I have an OSGi system running in Karaf, and was checking to which extend
> the deployment of feature packages (public packages like ActiveMQ, Camel,
> and my own features) could be performed via ACE instead of defining the
> configuration in Karaf config files on the targets. Start levels are
> heavily used in many Karaf feature definition files, and I assume there is
> a reason for that. But - to be honest - I have not yet tried to just deploy
> them using ACE and check which dependency issues might arise.
>
> Cheers,
> Jochen
>
> -----Original Message-----
> From: Marcel Offermans [mailto:marcel.offermans@luminis.nl]
> Sent: Monday, October 20, 2014 10:02 AM
> To: users@ace.apache.org; Philipp Buluschek
> Subject: Re: Defining start level for OSGi bundles
>
> Philipp is correct, it's an anti-pattern to *rely* on start levels for
> ordering the sequence in which bundles start. Some background and
> explanation can be found here [1]. This is also why ACE has no direct
> support for them: it should not ever be necessary to have them from a
> deployment aspect. Still, there are ways to make start levels work, as
> indicated below.
>
> I am curious, Jochen, what exactly is your use case?
>
> Greetings, Marcel
>
> [1] http://www.planetmarrs.net/start-levels-in-osgi/
> On 20 Oct 2014 at 9:46:02 , Philipp Buluschek (djbulu@gmail.com) wrote:
>
> Requoting Bram De Kruijff on this mailing list 22/09
>
> > - how can I assign a bundle start level to a bundle deployed by ACE?
>
> No, you can not as it is not covered by the specification. You could
> probably make it work using resource processors and/or a customized agent.
> However, in general start levels are considered to be an anti-pattern, so
> you should not use them anyway
>
> Regards Philipp
>
> On 20.10.2014 08:46, Walz, Jochen (ext) wrote:
> > Dear all,
> >
> > Apache Felix allows to define start levels for OSGi bundles
> (felix.auto.start.1=...). When bundles are deployed with ACE, is it
> possible to define the start level for each bundle? I haven't found
> something in the documentation so far.
> >
> > Kind Regards,
> > Jochen
> >
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>
> Knorr-Bremse Systeme für Schienenfahrzeuge GmbH
> Sitz: München
> Geschäftsführer: Dr. Robert Wassmer (Vorsitzender), Rolf Härdi, Dr. Peter
> Radina, Dr. Ralf Voss
> Vorsitzender des Aufsichtsrats: Dr. Dieter Wilhelm
> Registergericht München, HR B 91 181
>
> This transmission is intended solely for the addressee and contains
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> If you are not the intended recipient, please immediately inform the
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