I am evaluating several technologies for an open source app for the google app engine. I’m searching for information regarding OSGI on googles app engine.
I have found Lemmon but it seems to be a dead project. The last checkin was in mid 2009… :-/
There is also a eclipse blog entry from april 2009, but it’s not a real success story.
Has anyone successfully used OSGI in a GAE app?
I did some experiments on this, too, also see this question.
On top of various technical issues, GAE and OSGi are conceptually not a good fit at all. OSGi maintains a lot of internal state, such as which bundles are started, and has a really elaborate lifecycle. On GAE, your application is spread across multiple JVM and the JVM can be killed at any time. You would in effect have to recreate/synchronize the whole bundle startup process for every request.