David Jencks wrote:
On Sep 22, 2009, at 10:50 PM, Ivan wrote:
After reading some code changes of the geronimo-kenel in the sanbox,
I found that we keep the Geronimo kenel as an OSGI service, and each
Configuration ( or a bundle) will search it and start the
configuration as we do in the past while starting.
There's a difference in lifecycles between osgi bundles and geronimo
configurations.
OSGI:
bundles can be installed, in which case the classes are not available,
or started, in which case the classes are all available and the bundle
activator has been started. AFAICT there is no other built in
"no-really-start-it" state beyond "started". There might be more
less-started states I'm not aware of.
The extender model sort or introduces an additional state (or at least
the Blueprint extender does). After STARTED state, the extender kicks
in and processes metadata in the bundle and performs additional
actions. The completion point is when the BlueprintContainer service is
published to the service registry. At that point, the bundle state is
"complete". Something similar might make sense for a configuration,
where a "ConfigurationContainer" service is published to the registry
that would allow additional configuration operations to be performed.
Geronimo:
A Configuration is a gbean. You can't get much usefaul data out of it
until its started. Once it is started the classes are available and
you can find out what services (gbeans) are in the configuration and
look at their attributes. There's a further state of "all gbeans
started". The configuration manager treats these states as "loaded"
and "started"
Again, this maps fairly well to the model used by Blueprint extender.
The Configuration gbean could be published to the registry once it
reaches the "all gbeans started" state.
So far it seems to work to do something similar in the osgi
environment but it doesn't really fit very well yet. I'm not sure
where we will end up with this.
I have a feeling that, if we do that, Geronimo is still a part of
OSGI env, could we make the Geronimo is an OSGI env?
I don't understand what you are asking here. In the sandbox, geronimo
plugins are running in an osgi enviroment, and all the classes are
loaded from osgi bundles. Could you explain more what you are asking
about?
Could we publish GBeans as OSGI service via a ConfigurationActivator,
or though a GBean-OSGI adapter ?
I'm pretty sure we could, but I'd like to get more stuff working
before we decide if its a good idea. IIUC blueprint doesn't publish
every blueprint bean as an osgi service, but only ones you configure
to be published. I suspect we may want to, similarly, only publish
some gbeans as osgi services.
Your understanding is correct. Only the explicitly identified beans are
published as services. I suspect this would likely make sense within a
configuration context as well.
My current approach is to try to modify the existing geronimo
architecture relatively little where possible to get it to run in
osgi, respecting osgi architecture. So, I am trying to get stuff
working with the kernel as an osgi service, get the deployers working,
etc etc. I think after we have done this we will have a much better
idea what other work we want to try. For instance, we might not need
a kernel at all: possibly gbeans can just be osgi services with a few
extra attributes.
thanks
david jencks
Thanks !
2009/9/22 Rex Wang <[email protected] <mailto:[email protected]>>
Yes! hope for detail sharing :-)
-Rex
2009/9/22 Jack Cai <[email protected]
<mailto:[email protected]>>
David, that's exciting work!
It'll be great if you can share some more details. There are
a few puzzles that flow around my mind -
* Are we just taking OSGi framework in as another plug-in to
let it host OSGi applications? Or, vice-versa, we are
converting Geronimo into an OSGi application?
* If the latter case, will GBean go away?
* If yes, how much code changes are required? I'd say a lot ...
-Jack
On Tue, Sep 22, 2009 at 8:25 AM, David Jencks
<[email protected] <mailto:[email protected]>> wrote:
Over the weekend I got my sandbox osgi framework to build
and generate all the plugins as osgi bundles. This
involves running some of the geronimo server on
osgi/felix inside maven. The dependency management
system seems to work OK at least for starting bundles. I
also started doing a little bit of code cleanup.
I think the next step will be to get the framework server
running in standalone karaf or felix. Hopefully this
will be no harder than getting it running in embedded
felix in maven.
thanks
david jencks
--
Ivan
