I know there are some open source implementations of the config admin service (like from Apache Felix).
The problem with these implementations is that they are limited to a single server.
I am looking for an Enterprise ready implementation of the config admin service. It should support centralized configuration management. So basically I imagine having some configuration that is common to all servers and some configuration that is different for each cluster or server.
The Config Admin service is intended to run on a single server. This does not mean it cannot support configuration of multiple servers; it means that such “enterprise level” features should be part of a Management Agent that supplies data to the Config Admin service.
The problem is, everybody has different requirements for what that management agent needs to do. If you were to get an existing one it would probably not quite be right for your requirements. I would recommend writing one yourself; but this is relatively simple to do, since Config Admin takes care of the complex (but generic) task of managing config data within a single JVM, allowing you to concentrate on the features that are unique to your needs.
In other words: think modularity! Don’t try to expand Config Admin to make it do everything; just build components around it.