Showing posts from September, 2010

Two Karaf related Camel components

While thinking about a centralized logging system for Karaf and FUSE ESB, I had this idea that instead of using a built-in JMS appender, such as the one provided by Log4j, we could instead easily use Camel for that. Camel is really the best fit for such a thing, as we'd be able to add advanced things such as redelivery, batching, compression and choose easily the transport we want (JMS or plain TCP).

The OSGi EventAdmin service is also an important point for monitoring events in the OSGi runtime, as most of the OSGi services do publish events to it (Blueprint bundles events, bundle events, etc...). So this was another need for a camel component.

Given Camel 2.5 will be released soon, I did not want to destabilize trunk just before the release so I've committed them to a github fork for now.

Those two components are really easy to use:

<blueprint xmlns="">
<camelcontext xmlns="…

Introducing Cade, the Config ADmin Extender

The OSGi Alliance is working on enhancements to the OSGi ConfigAdmin and some of the experimentation have been unveiled by Peter Kriens in a recent blog. The point is I was in need for enhancing the Apache Karaf blueprint configurations to be more dynamic, for example to restart the SSH server if its configuration had changed.

So I decided to start hacking on this idea and create cade, the Config ADmin Extender. The project is really small and allows you to easily access OSGi configurations in a type-safe manner. It seems to work quite well, so I plan to start using it in Karaf for the various parts that need a bit of dynamism for handling configuration changes.

I haven't done any release yet, but I hope to do that really soon. The source code is Apache Licensed, so feel free to have a look and provide feedback.


Over the last months, I’ve been pondering over the use of OBR, the OSGi Bundle Repository. OBR describes resources (mostly OSGi bundles) in terms of capabilities and requirements. The OBR resolver is able to find the list of bundles needed to fulfill a given bundle requirements. This allows deploying a bundle and its required dependencies without caring too much about the exact dependencies being deployed. In addition, it takes into account the already locally installed bundles and thus reduces unneeded duplication of libraries in different versions.

When I started to use the Felix OBR repository earlier this year, I quickly ran into performance problems during both the parsing phase and the resolution phase. It was nearly unusable for repositories more than a few dozens of resources, which mean in real world scenarii. So I spent some time optimizing things a bit. I also enhanced the API to provide more meaningful informations and to allow more control over the resolution. That…