OSGI on Google engine?

Question

I evaluate several technologies for an open source application for the Google engine. I am looking for information about OSGI in the Google engine.

I found Lemmon , but it seems to be a dead project. The last check was in mid-2009 ...: - / There is also an eclipse blog entry since April 2009, but this is not a real success story.

Has anyone successfully used OSGI in a GAE app?

Answer 1

I did some experiments about this, also see this question .

In addition to various technical issues, GAE and OSGi are not conceptually compatible. OSGi maintains a lot of internal state, for example, which packages are running and has a very complex life cycle. In GAE, your application extends to multiple JVMs, and JVMs can be killed at any time. In fact, you will have to recreate / synchronize the entire package launch process for each request.

Answer 2

The biggest problem with this is the incompatibility between OSGi and GAE regarding flow control.

GAE manages threads (and machines) for you and makes it tough / controllable as you handle threads in your own application. OSGi really does the opposite.

Answer 3

I did not use OSGI on GAE, however I had a suggestion that you can try to do a hasty proof of concepts using Lemmon (or other implementations). Basically, try it.

As I understand it, you can set up the Google App Engine website for free. I would take advantage of this and make the proof of the concept as quick as possible.

Keep in mind that some open source projects will not have permanent accounts. Sometimes, when an open source project does what the author intended to do, development stops until something new is needed. The next registration cannot be carried out for several months, when the initial requirements of the developer change or, perhaps, the adopter on the basis of the code detects a problem.