From a high level, ZooKeeper can be seen as a replicated tree, and Fabric uses this tree to store the configuration of the various agents (we call Agent, any Karaf instance connected to the same Fabric cluster). Fabric defines a notion of profile, which is a "kind" of agent. We can define different profiles for various applications we want to deploy in Karaf, for example an ActiveMQ broker or a web server. A given agent can be assigned multiple profiles, allowing a single Karaf instance to serve multiple purposes. To configure a Karaf instance, Fabric uses the ConfigAdmin OSGi service which is the standard way to push configurations to OSGi applications. An agent will have a bundle deployed which will monitor the ZooKeeper tree and update the configurations according to the profiles it has been assigned. Each bundle will then automatically be notified of the changes through the ConfigAdmin service. It is often the case that configurations are mostly the same between sever
Showing posts from May, 2011
- Other Apps
I'm very pleased to introduce FuseSource Fabric , a distributed configuration, management and provisioning system for the products supported by FuseSource : Apache ServiceMix , Apache Camel , Apache ActiveMQ and Apache CXF . The user's guide contains lots of informations, so I won't rewrite it all again, but I instead invite you to have a quick look at it. The core Fabric is deployed on top of Apache Karaf and heavily reuses the very mature Apache ZooKeeper project. I'm really excited about Fabric. I've been working on it since Apache Karaf 2.2.0 has been released and I'm glad to share this work. I won't add much more for now, but stay tuned as I plan to write a number of posts explaining the various parts of Fabric.
- Other Apps
I just want to point out the great conference FuseSource is sponsoring around open source integration and especially Apache Camel. Unfortunately, I won't be able to attend the event as my wife is expecting our sixth child in the coming weeks :-). That would have been a great opportunity to have my copy of the EIP book signed by Gregor though. You should definitely go there and listen to all the great speakers . Click on the image below for more informations.