[IPython-dev] [sage-notebook] Re: Using Google App Engine channels instead of zmq in new IPython

[Jason Grout]

On 2/13/12 4:48 PM, Fernando Perez wrote:
> On Mon, Feb 13, 2012 at 2:32 PM, Brian Granger<ellisonbg at gmail.com>  wrote:
>> At this point, ZeroMQ is not a minor implementation detail of IPython,
>> it is really our secret sauce.  ZeroMQ has abstractions, such as
>> queues and messaging patterns, that go beyond simple point to point
>> messaging and we rely on those throughout the code base.  I don't see
>> how ZeroMQ could be replaced without rewriting good parts of IPython.
>
> Very true.  Furthermore, we are working on integrating more and more
> the code that runs a single interactive kernel with that used by
> engines in a parallel setting, to make use of the parallel tools more
> seamless with the rest of our clients (notebook, qt console, etc).
> And the parallel code is pretty much unthinkable without zeromq, as
> this diagram should make fairly clear:
>
> http://ipython.org/ipython-doc/dev/development/parallel_connections.html

Those are some very nice diagrams!


>
> So I concur with Brian, that pulling zmq out of ipython is probably
> not a very realistic goal, and at least it's not one that we have in
> our radar to commit any effort towards.  Obviously the code is all
> there, and if you find ways of using IPython successfully for Sage
> without zmq, that's great.  I just think that from our side, there
> won't be work put in that direction, given how many other things are
> on our plate and how much we continue to build *upon* zmq rather than
> wanting to move away from it.

Thanks for the feedback.  We already have a websocket<->zmq bridge, 
right?  I think now that GAE channels could basically replace the 
websocket portion.  I assume that would be much easier?  So the basic 
architecture would be:

browser <-GAE channel-> Sage server on GAE <-GAE channel-> (bridge 
<-ZMQ-> IPython kernel)

where the part in parentheses would be the worker running on a compute 
server, and the shim is the bridge between GAE channels and zmq.  Does 
that seem more reasonable?  What does the architecture of your websocket 
bridge look like?

Thanks,

Jason