[IPython-dev] pyzmq problems

[Brian Granger]

I guess I am not clear why the kernel needs to have the SUB socket.
If the client needs to send a message to the kernel, can't it simply
use the REQ/REP channel?  But I do think the kernel needs the REP and
PUB sockets.

Brian

2010/5/24 Omar Andrés Zapata Mesa <andresete.chaos at gmail.com>:
> I have now read the zmq doc from zmq`s website reference.
> I think we need to use for the kernel 3 ports for the communication system.
> Kernel description:
>  http://github.com/omazapa/ipython/blob/master/IPython/core/ipzmq_server.py
> -> port 5555 have subscribe socket into kernel class to read publisher
> messages from frontend.
>
>
>
>
>
> self._subscribe_socket = self._Context.socket(zmq.SUB)
>
> self._subscribe_socket.bind(self._subscribe_connection)
>
> self._subscribe_socket.setsockopt(zmq.SUBSCRIBE,"")
>
>
>
>
>
>
> since the subscribe socket can not send messages "it was read in the
> reference", we need to implement another socket called publisher to send
> messages to frontend, then
>
>
> -> port 5556 has a socket which allow kernel class to send messages to
> frontend, then the subbscribe and publisher sockets will communicate.
>
>
>
> self._publisher_socket = self._Context.socket(zmq.PUB)
>
> self._publisher_socket.bind(self._publisher__connection)
>
>
> -> and 5557 will be implemented to request and publisher sockets that are
> working very well.
>
> do you think this 3-socket model is a good idea? You can check it because
> I've already implemented it an and it's working fine.
> http://github.com/omazapa/ipython/blob/master/IPython/core/ipzmq_client.py
> O.
> El 24 de mayo de 2010 13:49, Brian Granger <ellisonbg at gmail.com> escribió:
>>
>> Omar,
>>
>> I am busy today but here are some ideas:
>>
>> * To get to know pyzmq better, I would open up 2-3 IPython sessions,
>> import zmq on all of them and then start to create sockets and send
>> messages between the different IPython sessions.  This works really
>> well and will give you a better idea of how the different socket types
>> work, how the json stuff works, etc.  This would be invaluable.
>>
>> * To simplify debugging, create a version of the code that has the
>> absolute minimal code - no objects, config, etc.  Just the raw zmq
>> messaging stuff.
>>
>> I think if you do these 2 things, the error will be more obvious.
>> Keep posting back to the list so I or Fernando can help with this
>> though.
>>
>> Cheers,
>>
>> Brian
>>
>> 2010/5/22 Omar Andrés Zapata Mesa <andresete.chaos at gmail.com>:
>> > hi all
>> > I am working yet in zmq module to ipython, but I have the next problem
>> > using
>> > json.
>> > the code are in http://github.com/omazapa/ipython
>> > into the dir  ipython/IPython/core/
>> >
>> > I run my zmq server prototype
>> >
>> > the output is
>> >
>> > omazapa at tuxhome:~/MyProjects/GSoC/tmp/ipython/IPython/core$ python
>> > ipzmq_server.py
>> > reply socket= tcp://127.0.0.1:5555
>> > publisher socket = tcp://127.0.0.1:5556
>> > Server started.
>> >
>> >
>> > in this moment I am waiting json`s message in reply socket.
>> >
>> >
>> > then I run my client prototype
>> >
>> > the output is
>> >
>> > omazapa at tuxhome:~/MyProjects/GSoC/tmp/ipython/IPython/core$ python
>> > ipzmq_client.py
>> > request socket = tcp://127.0.0.1:5556
>> > subscribe socket = tcp://127.0.0.1:5555
>> >
>> >
>> > but server no recieve the message.
>> >
>> > the output is
>> >
>> > Traceback (most recent call last):
>> >   File "ipzmq_server.py", line 112, in <module>
>> >     msg=server.recieve_reply()
>> >   File "ipzmq_server.py", line 79, in recieve_reply
>> >     msg=self._reply_socket.recv_json()
>> >   File "_zmq.pyx", line 709, in zmq._zmq.Socket.recv_json
>> > (zmq/_zmq.c:5242)
>> >   File "/usr/lib/python2.6/json/__init__.py", line 307, in loads
>> >     return _default_decoder.decode(s)
>> >   File "/usr/lib/python2.6/json/decoder.py", line 319, in decode
>> >     obj, end = self.raw_decode(s, idx=_w(s, 0).end())
>> >   File "/usr/lib/python2.6/json/decoder.py", line 338, in raw_decode
>> >     raise ValueError("No JSON object could be decoded")
>> > ValueError: No JSON object could be decoded
>> >
>> >
>> > have you some idea?
>> > maybe, do I need encode my message before send it?
>> > I have the last version of zeromq2 from official repo and pyzmq
>> > http://github.com/ellisonbg/pyzmq/, I am using python2.6
>> >
>> > Brian  said me that the problem is that I have outdated version of
>> > zeromq
>> > and pyzmq but I update zeromq and pyzmq and It is not working yet.
>> >
>> >
>> > thks
>> >
>> > _______________________________________________
>> > IPython-dev mailing list
>> > IPython-dev at scipy.org
>> > http://mail.scipy.org/mailman/listinfo/ipython-dev
>> >
>> >
>>
>>
>>
>> --
>> Brian E. Granger, Ph.D.
>> Assistant Professor of Physics
>> Cal Poly State University, San Luis Obispo
>> bgranger at calpoly.edu
>> ellisonbg at gmail.com
>
>



-- 
Brian E. Granger, Ph.D.
Assistant Professor of Physics
Cal Poly State University, San Luis Obispo
bgranger at calpoly.edu
ellisonbg at gmail.com