Exploring Cometd

[bugsy....@gmail.com]

Is there any documentation available to explore this framework?. How
scalable is the python based system?

I have developed a collaborative application using nevow but I would
like to see if I can use the dojo+bayeux approach since it looks
simpler. I wonder how we plugin the existing application into this
system.

thanks
bugz

[David Ascher]

I suspect it really depends on the details of your app. You can just
have your app subscribe to channels the way your clients do, and use
comet as a bus. Or you can build more logic into the server itself --
in which case, "read the source, luke".

Comet isn't an app server, or even a framework. It's a spec for
persistent server/client communication, with some reference
implementations in a couple of languages.

re: the scalability of the python implementation, my guess at this
point is that it'll scale quite well in a single-node setup as it's
"nothing more" than a single-process twisted server. I don't know of
any quantitative results yet.

Scaling across multiple boxes using Python is probably going to
require something like integration with the Spread toolkit or some
other group communication framework, and AFAICT that's still a
"research" area.

-david

[Harish Krishnan]

Hi David,
Certain types of messages sent by my application are processed at the
server end. You could view it as a application level protocol over
Bayeux protocol. Hence the subscribe model doesnt satisfy the
requirements.

I did look at the code and I guess its fairly simple to add some
python serverside processing but I was wondering if there is a best
practice out there.

One of the advantages that Alex had mentioned in the nevow forums
about cometd was that developers could just plugin their native
application ( may be Ruby on rails) and use cometd as the messaging
server. I hope there would be more information that can help people
like me to experiment with more easily, infact I would be interested
in contributing to that effort.

Cometd is quite simpler to deal with compared to the learning curve
that I had to go through for nevow. Great work guys and thanks for the
help.

bugz..