Charles,
What is the machine configuration you're running on? It seems that there
are two MCA parameter for the tcp btl: btl_tcp_if_include and
btl_tcp_if_exclude (see ompi_info for details). There may be other knobs
I'm not aware of. If you're using UCX then my guess is that UCX has its
own way to choose the network interface to be used...
Cheers
Joseph
On 9/1/20 9:35 PM, Charles Doland via users wrote:
Yes. It is not unusual to have multiple network interfaces on each host
of a cluster. Usually there is a preference to use only one network
interface on each host due to higher speed or throughput, or other
considerations. It would be useful to be able to explicitly specify the
interface to use for cases in which the MPI code does not select the
preferred interface.
Charles Doland
charles.dol...@ansys.com <mailto:charles.dol...@ansys.com>
(408) 627-6621 [x6621]
------------------------------------------------------------------------
*From:* users <users-boun...@lists.open-mpi.org> on behalf of John
Hearns via users <users@lists.open-mpi.org>
*Sent:* Tuesday, September 1, 2020 12:22 PM
*To:* Open MPI Users <users@lists.open-mpi.org>
*Cc:* John Hearns <hear...@gmail.com>
*Subject:* Re: [OMPI users] Limiting IP addresses used by OpenMPI
*[External Sender]*
Charles, I recall using the I_MPI_NETMASK to choose which interface for
MPI to use.
I guess you are asking the same question for OpenMPI?
On Tue, 1 Sep 2020 at 17:03, Charles Doland via users
<users@lists.open-mpi.org <mailto:users@lists.open-mpi.org>> wrote:
Is there a way to limit the IP addresses or network interfaces used
for communication by OpenMPI? I am looking for something similar to
the I_MPI_TCP_NETMASK or I_MPI_NETMASK environment variables for
Intel MPI.
The OpenMPI documentation mentions the btl_tcp_if_include
and btl_tcp_if_exclude MCA options. These do not appear to be
present, at least in OpenMPI v3.1.2. Is there another way to do
this? Or are these options supported in a different version?
Charles Doland
charles.dol...@ansys.com <mailto:charles.dol...@ansys.com>
(408) 627-6621 [x6621]
