[Opengeoscience-developers] Websockets and MPI

[Aashish Chaudhary]

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
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