[Opengeoscience-developers] Websockets and MPI

Wed Feb 27 13:43:27 EST 2013

It works now. I had bad installation of mpi and then on top of that I got
the wrong text pasted on the pi.py file.

Thanks. Have you plan the next steps?

On Wed, Feb 27, 2013 at 1:39 PM, Aashish Chaudhary <
aashish.chaudhary at kitware.com> wrote:

> Found the problem (and pasted one file wrong)
>
>
> On Wed, Feb 27, 2013 at 1:38 PM, Aashish Chaudhary <
> aashish.chaudhary at kitware.com> wrote:
>
>> yes,
>>
>> *pi.py*
>> from mpi4py import MPI
>> import numpy
>>
>> comm = MPI.Comm.Get_parent()
>> size = comm.Get_size()
>> rank = comm.Get_rank()
>>
>> N = numpy.array(0, dtype='i')
>> comm.Bcast([N, MPI.INT], root=0)
>> h = 1.0 / N; s = 0.0
>> for i in range(rank, N, size):
>>     x = h * (i + 0.5)
>>     s += 4.0 / (1.0 + x**2)
>> PI = numpy.array(s * h, dtype='d')
>> comm.Reduce([PI, MPI.DOUBLE], None,
>>             op=MPI.SUM, root=0)
>>
>> comm.Disconnect()
>>
>> *cpi.py*
>> #!/usr/bin/env python
>> from  mpi4py import MPI
>> import numpy
>>
>> comm = MPI.Comm.Get_parent()
>> size = comm.Get_size()
>> rank = comm.Get_rank()
>>
>> N = numpy.array(0, dtype='i')
>> comm.Bcast([N, MPI.INT], root=0)
>> h = 1.0 / N; s = 0.0
>> for i in range(rank, N, size):
>>     x = h * (i + 0.5)
>>     s += 4.0 / (1.0 + x**2)
>> PI = numpy.array(s * h, dtype='d')
>> comm.Reduce([PI, MPI.DOUBLE], None,
>>             op=MPI.SUM, root=0)
>>
>>  comm.Disconnect()
>>
>>
>>
>>
>> On Wed, Feb 27, 2013 at 1:29 PM, Ben Burnett <benjam.arlyn at gmail.com>wrote:
>>
>>> When you ran the example, did you create two python files, one for the
>>> master (e.g. pi.py), one for the worker (cpi.py), and then run the master
>>> file?
>>>
>>>
>>> On Wed, Feb 27, 2013 at 1:23 PM, Aashish Chaudhary <
>>> aashish.chaudhary at kitware.com> wrote:
>>>
>>>> That's what I did to verify..here is the error I got:
>>>>
>>>> Traceback (most recent call last):
>>>>   File "test.py", line 5, in <module>
>>>>     size = comm.Get_size()
>>>>   File "Comm.pyx", line 68, in mpi4py.MPI.Comm.Get_size
>>>> (src/mpi4py.MPI.c:57940)
>>>> mpi4py.MPI.Exception: Invalid communicator, error stack:
>>>> MPI_Comm_size(111): MPI_Comm_size(MPI_COMM_NULL, size=0x7fffeda7bd3c)
>>>> failed
>>>> MPI_Comm_size(69).: Null communicator
>>>>
>>>>
>>>> On Wed, Feb 27, 2013 at 1:14 PM, Ben Burnett <benjam.arlyn at gmail.com>wrote:
>>>>
>>>>> The Pi example came from
>>>>> http://mpi4py.scipy.org/docs/usrman/tutorial.html, I just modified it
>>>>> to run in a websocket handler on cherrypy.
>>>>>
>>>>> It looks like it's failing to spawn the processes using MPI. Do you
>>>>> get any exceptions in the log?
>>>>>
>>>>> You could try first running the Pi example from the above website in
>>>>> python to make sure MPI is working on your machine.
>>>>>
>>>>>
>>>>> On Wed, Feb 27, 2013 at 12:46 PM, Aashish Chaudhary <
>>>>> aashish.chaudhary at kitware.com> wrote:
>>>>>
>>>>>> @Ben,
>>>>>>
>>>>>> The char exampled worked like charm, but the PI example didn't.  I
>>>>>> don't see the value of PI. Did you write that code or its from the ws4py
>>>>>> test / example?
>>>>>>
>>>>>>  Thanks
>>>>>>
>>>>>>
>>>>>>   1 [27/Feb/2013:12:44:38] ENGINE Listening for SIGHUP.
>>>>>>   2 [27/Feb/2013:12:44:38] ENGINE Listening for SIGTERM.
>>>>>>   3 [27/Feb/2013:12:44:38] ENGINE Listening for SIGUSR1.
>>>>>>   4 [27/Feb/2013:12:44:38] ENGINE Bus STARTING
>>>>>>   5 [27/Feb/2013:12:44:38] ENGINE Forking once.
>>>>>>   6 [27/Feb/2013:12:44:38] ENGINE Forking twice.
>>>>>>   7 [27/Feb/2013:12:44:38] ENGINE Daemonized to PID: 24810
>>>>>>   8 [27/Feb/2013:12:44:38]  Starting WebSocket processing
>>>>>>   9 [27/Feb/2013:12:44:38] ENGINE PID 24810 written to
>>>>>> '/home/aashish/workspace/build/deploy/ogs.pid'.
>>>>>>  10 [27/Feb/2013:12:44:38] ENGINE Started monitor thread
>>>>>> '_TimeoutMonitor'.
>>>>>>  11 [27/Feb/2013:12:44:38] ENGINE Started monitor thread
>>>>>> 'Autoreloader'.
>>>>>>  12 [27/Feb/2013:12:44:38] ENGINE Serving on 127.0.0.1:8080
>>>>>>  13 [27/Feb/2013:12:44:38] ENGINE Bus STARTED
>>>>>>  14 [27/Feb/2013:12:44:41]  Handler created:
>>>>>> <websocket_pi.PiWebSocketHandler object at 0x275f410>
>>>>>>  15 [27/Feb/2013:12:44:41]  Managing WebSocket connection from
>>>>>> 127.0.0.1:56898
>>>>>>  16 [27/Feb/2013:12:44:46]  something
>>>>>>  17 [27/Feb/2013:12:44:46]  Recieved message 101
>>>>>>  18 [27/Feb/2013:12:44:46]  Dir /home/aashish/workspace/build/deploy
>>>>>>  19 [27/Feb/2013:12:44:46]  Path
>>>>>> /home/aashish/workspace/build/deploy/cpi.py
>>>>>>
>>>>>> On Wed, Feb 27, 2013 at 12:15 PM, Aashish Chaudhary <
>>>>>> aashish.chaudhary at kitware.com> wrote:
>>>>>>
>>>>>>> Nice..I will have a look at it today.
>>>>>>>
>>>>>>> On Wed, Feb 27, 2013 at 12:10 PM, Ben Burnett <
>>>>>>> benjam.arlyn at gmail.com> wrote:
>>>>>>>
>>>>>>>> I just pushed the branch websockets-mpi, and added a wiki page with
>>>>>>>> some notes on it
>>>>>>>> https://github.com/OpenGeoscience/opengeoscience/wiki/Testing-Websockets-and-MPI
>>>>>>>> _______________________________________________
>>>>>>>> Opengeoscience-developers mailing list
>>>>>>>> Opengeoscience-developers at public.kitware.com
>>>>>>>>
>>>>>>>> http://public.kitware.com/cgi-bin/mailman/listinfo/opengeoscience-developers
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> | Aashish Chaudhary
>>>>>>> | R&D Engineer
>>>>>>> | Kitware Inc.
>>>>>>> | www.kitware.com
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> | Aashish Chaudhary
>>>>>> | R&D Engineer
>>>>>> | Kitware Inc.
>>>>>> | www.kitware.com
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> | Aashish Chaudhary
>>>> | R&D Engineer
>>>> | Kitware Inc.
>>>> | www.kitware.com
>>>>
>>>
>>>
>>
>>
>> --
>> | Aashish Chaudhary
>> | R&D Engineer
>> | Kitware Inc.
>> | www.kitware.com
>>
>
>
>
> --
> | Aashish Chaudhary
> | R&D Engineer
> | Kitware Inc.
> | www.kitware.com
>

-- 
| Aashish Chaudhary
| R&D Engineer
| Kitware Inc.
| www.kitware.com
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