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From: George Bosilca (bosilca_at_[hidden])
Date: 2006-07-11 14:53:24


The MPI standard definition of a port is not the one you expect. It
is nothing like a TCP port, even if they support similar operations
(open and close). This port is an opaque value (however MPI stadard
define it as being a TEXT) than will be used internally by the MPI
library in order to allow you to connect to the remote application.
Moreover, contrary to other MPI library, Open MPI allow you to
publish and connect over networks that are not Ethernet based (such
as Myrinet, Infiniband ...).

If you want to know how to find such a port once it is published by
one MPI application read the MPI_Lookup_name (http://www.ualberta.ca/
AICT/RESEARCH/LinuxClusters/doc/mpich2/www3/MPI_Lookup_name.html).

   Good luck,
     George.

On Jul 11, 2006, at 2:40 PM, Abhishek Agarwal wrote:

> I have a seprate process which is not linked to this process and hence
> doesnot know anything about this MPI process. I wants to receive
> some data
> for this server process.
>
> Hence I wanted to know if i could specify a specific port. I have used
> MPI_publish and it seem to work fine.
>
> Please advice further is there is a way to start a service at a
> particular
> port.
>
> Thanks
> Abhishek
>
>
>> From: Edgar Gabriel <gabriel_at_[hidden]>
>> Reply-To: Open MPI Users <users_at_[hidden]>
>> To: Open MPI Users <users_at_[hidden]>
>> Subject: Re: [OMPI users] MPI_Info for MPI_Open_port
>> Date: Tue, 11 Jul 2006 13:29:53 -0500
>>
>> John Robinson wrote:
>>> The MPI publish/lookup calls should handle this, if OpenMPI has
>>> them. I
>>> haven't tried this with OpenMPI yet, but it claims MPI-2 compilance,
>>> right? ;-)
>>
>> of course, but MPI does not say what an MPI port has to be. For
>> Open MPI
>> this is *not* equal to a TCP port number... So you can open a port,
>> publish it, and another process can look this port-name up
>>
>>>
>>> /jr
>>> ---
>>> Ralph H Castain wrote:
>>>> On 7/11/06 11:59 AM, "Edgar Gabriel" <gabriel_at_[hidden]> wrote:
>>>>
>>>>
>>>>> Abhishek Agarwal wrote:
>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> Is there a way of providing a specific port number in MPI_Info
>>>>>> when using a MPI_Open_port command so that clients know which
>>>>>> port number to connect.
>>>>> the MPI port-name in Open MPI has nothing to do with a TCP port
>>>>> number. The port-name right now is a combination of the process
>>>>> name ( a tuple of cell id, job id and process id) and a tag used
>>>>> for the communication.
>>>>>
>>>>> Maybe somebody from the RTE group could comment on whether
>>>>> there is
>>>>> a possibility to specify a specific port number for OOB
>>>>> communication, I am not aware of any right now...
>>>>
>>>> I'm afraid not - the port number for OOB communications is
>>>> determined
>>>> dynamically be each process, and then communicated between them.
>>>>
>>>> I'm not sure what your intended purpose is here, of course, but you
>>>> don't need to worry about your process being able to "talk" via the
>>>> OOB - it's all done automatically during launch.
>>>>
>>>> Ralph
>>>>
>>>>
>>>>
>>>>> Thanks Edgar
>>>>>
>>>>>
>>>>>> Do advice of any solution so that we can create the portname
>>>>>> inside the client once we know the port number of server.
>>>>>>
>>>>>> Thanks Abhishek
>>>>>>
>>>>>>
>>>>>> _______________________________________________ users mailing
>>>>>> list users_at_[hidden]
>>>>>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>>>> _______________________________________________ users mailing list
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>>>>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>>>
>>>>
>>>> _______________________________________________ users mailing list
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>>>> users
>>> _______________________________________________
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>>
>> --
>> Edgar Gabriel
>> Assistant Professor
>> Department of Computer Science email:gabriel_at_[hidden]
>> University of Houston http://www.cs.uh.edu/~gabriel
>> Philip G. Hoffman Hall, Room 524 Tel: +1 (713) 743-3857
>> Houston, TX-77204, USA Fax: +1 (713) 743-3335
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>
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