Also, I finally got some graphical output from Sun Studio Analyzer.
I
see MPI_Recv and MPI_Wait taking a lot of time, but I would think that
is ok, this program does heavy number crunching and I would expect it to
need to Wait or wait to Receive very often since there is a decent
amount of time between communications. Is this the correct assumption?
What
does catch my eye is MPI_Barrier takes up a significant chunk of around
10%. I read that MPI_Barrier blocks the caller until all processes have
called? Perhaps there is something fishy there that it is taking an
awful long time for processes to call each other although MPI_Send is
not taking very long so it makes me feel more comfortable about network
communication.
Anyways, please have a look and let me know what
you think could be the issue.
Regards,
Robert
Walters
--- On Tue, 7/13/10, Robert Walters <raw19...@yahoo.com> wrote:
From: Robert Walters <raw19...@yahoo.com>
Subject: Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
List-Post: users@lists.open-mpi.org
Date: Tuesday, July 13, 2010, 10:42 PM
Naturally, a forgotten attachment.
An to edit that, it was compiled to be used with OpenMPI 1.4.1, but as I
understand, 1.4.2 is just a bug fix of 1.4.1.
--- On Tue, 7/13/10, Robert Walters <raw19...@yahoo.com> wrote:
From: Robert Walters <raw19...@yahoo.com>
Subject: Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
List-Post: users@lists.open-mpi.org
Date: Tuesday, July 13, 2010, 10:38 PM
I think I forgot to mention earlier that the application I am using is
pre-compiled. It is a finite element software called LS-DYNA. It is not open
source and I likely cannot obtain the code
it uses for MPP. This version I am using was specifically compiled, by the
parent company, for OpenMPI 1.4.2 MPP operations.
I recently installed the Sun Studio 12.1 to attempt to analyze the situation.
It seems to work partially. It will record various processes individually,
which is cryptic. The function it fails on, though, is the MPI Tracing. It
errors that "no MPI tracing data file in experiment, MPI Timeline and MPI
Charts will not be available". Sometime during the analysis (about 10,000
iterations later, the VT_MAX_FLUSHES complains that there are too many i/o
flushes and its not happy. I've increased this number in the environmental
variable and killed the
analysis before it had a chance to error but still no MPI Trace data is
recorded. Not sure if you guys have heard of that happening or know any way to
fix it...Did OpenMPI need to be configured/built for Sun Studio use?
I also noticed that from the data I do get back, there are two sets of
functions for everything. There is mpi_recv and then my_recv_, both with the
same % utilization time. The mpi one comes from your program's library and the
my_recv_ one comes from my program. Is that typical or should the program I'm
using be saying mpi_recv only? This data may be enough to help me see what's
wrong so I will pass it along. Keep in mind this is percent time of total run
time and not percent of MPI communication. I attached the information in a
picture rather than me attempting to format a nice table in this nasty e-mail
application.
I blacked out items that are related to LS-DYNA but afterward I just realized
that I think every function with
an _ at the end represents a command issuing from LS-DYNA.
These are my big spenders. The processes I did not include are in the bottom
4%. The processes that would be above these were the LS-DYNA applications at
100%. Like I mentioned earlier, there are two instances of every MPI command,
and they carry the same percent usage. It's curious that this version, built
for OpenMPI, uses different functions.
Just for a little more background info, OpenMPI is being launched from a local
hard drive on each machine, but the LS-DYNA job files, and related data output
files, are on a mounted drive on that machine, where the mounted drive is
located on a different machine also in the cluster. We were thinking that might
be an issue but it isn't writing enough data for me to think that would
significantly decrease MPP performance.
I would like to make one last mention. That is that OpenMPI running 8 cores on
a single node, with all the
communication, works flawlessly. It works much faster than the Shared Memory
Parallel (SMP) version of LS-DYNA that we currently have used scaled to 8
cores. LS-DYNA seems to be approximately 25% faster (don't quote me on that)
when using the OpenMPI installation than when using the standard SMP, which is
awesome. My point being that OpenMPI seems to be working fine, even with the
screwy mounted drive. This leads me to continue to point at the network.
Anyhow, let me know if anything seems weird on the OpenMPI communication
subroutines. I don't have any numbers to lean on from experience.
Sorry this e-mail was long. Thank you again for all of your help.
Regards,
Robert Walters
--- On Tue, 7/13/10, David Zhang <solarbik...@gmail.com> wrote:
From: David Zhang <solarbik...@gmail.com>
Subject:
Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
List-Post: users@lists.open-mpi.org
Date: Tuesday, July 13, 2010, 9:42 PM
Like Ralph says, the slow down may not be coming from the kernel, but rather on
waiting for messages. What MPI send/recv commands are you using?
On Tue, Jul 13, 2010 at 11:53 AM, Ralph Castain <r...@open-mpi.org> wrote:
I'm afraid that having 2 cores on a single machine will always outperform
having 1 core on each machine if any communication is involved.
The most likely thing that is happening is that OMPI is polling waiting for
messages to arrive. You might look closer at your code to try and optimize it
better so that number-crunching can get more attention.
Others on this list are far more knowledgeable than I am about doing such
things, so I'll let them take it from here. Glad it is now running!
On Jul 13, 2010, at 12:22 PM, Robert Walters wrote:
OpenMPI,
Following up. The sysadmin opened ports for machine to machine communication
and OpenMPI is running successfully with no errors in connectivity_c, hello_c,
or ring_c. Since, I have started to implement our MPP software (finite element
analysis) that we have, and upon running a simple, 1 core on machine1, 1 core
on machine2, job, I notice it is considerably slower than a 2 core job on a
single machine.
A quick look at top shows me kernel usage is almost twice what cpu usage is! On
a 16 core job, (8 cores per node so 2 nodes total) test, OpenMPI was consuming
~65% of the cpu for kernel related items rather than number-crunching related
items...Granted, we are running on GigE, but this is a finite element code we
are running with no heavy data transfer within it. I'm looking into
benchmarking tools, but my sysadmin is not very open to
installing third party softwares. Do you have any suggestions for what I can
use that would be "big name" or guaranteed safe tools I can use to figure out
what's causing the hold up with all the kernel usage? I'm pretty sure its
network traffic but I have no way of telling (as far as I know because I'm not
a Linux whiz) with the standard tools in RHEL.
Thanks for all the help! I'm glad to get it finally working and I think with a
little tweaking it should be ready to go very soon.
Regards,
Robert Walters
--- On Sat, 7/10/10, Ralph Castain <r...@open-mpi.org> wrote:
From: Ralph Castain <r...@open-mpi.org>
Subject: Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
List-Post: users@lists.open-mpi.org
Date: Saturday, July 10, 2010, 4:37 PM
The "static ports" flag means
something different - it is used when the daemon is given a fixed port to use.
In some installations, we lock every daemon to the same port number so that
each daemon can compute exactly how to contact its peers (i.e., no contact info
exchange required for wireup).
You have a "fixed range", but not "static port", scenario. Hence the message.
Let us know how it goes - I agree it sounds like something to discuss with the
sysadmin.
On Jul 10, 2010, at 1:47 PM, Robert Walters wrote:
I ran oob_tcp_verbose 99 and I am getting something interesting I never got
before.
[machine 2:22347] bind() failed: no port available in the range [60001-60016]
[machine 2:22347] mca_oob_tcp_init: unable to create IPv4
listen socket: Error
I never got that error before we messed with the iptables but now I get that
error... Very interesting, I will have to talk to my sysadmin again and make
sure he opened the right ports on my two test machines. It looks as though
there are no open ports. Another interesting thing is I see that the Daemon is
still report:
Daemon [[28845,0],1] checking in as pid 22347 on host machine 2
Daemon [[28845,0],1] not using static ports
Which, I may be misunderstanding, should have been taken care of when I
specified what ports to use. I am telling it a static set of ports... Anyhow, I
will get with my
sysadmin again and see what he says. At least OpenMPI is correctly
interpreting the range.
Thanks for the help.
--- On Sat, 7/10/10, Ralph Castain <r...@open-mpi.org> wrote:
From: Ralph Castain <r...@open-mpi.org>
Subject: Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
Date: Saturday, July 10, 2010, 3:21 PM
Are there multiple interfaces on your nodes? I'm wondering if we are using a
different network
than the one where you opened these ports.
You'll get quite a bit of output, but you can turn on debug output in the oob
itself with -mca oob_tcp_verbose xx. The higher the number, the more you get.
On Jul 10, 2010, at 11:14 AM, Robert Walters wrote:
Hello again,
I believe my administrator has opened the ports I requested. The problem I am
having now is that OpenMPI is not listening to my defined port assignments in
openmpi-mca-params.conf (looks like permission 644 on those files should it be
755?)
When I perform netstat -ltnup I see that orted is listening 14 processes in tcp
but scaterred in the 26000ish port range when I specified 60001-60016 in the
mca-params file. Is there a parameter I am missing? In any case I
am still hanging as mentioned originally even with the port forwarding enabled
and specifications in mca-param enabled.
Any other ideas on what might be causing the hang? Is there a more verbose mode
I can employ to see more deeply into the issue? I have run --debug-daemons and
--mca plm_base_verbose
99.
Thanks!
--- On Tue, 7/6/10, Robert Walters
<raw19...@yahoo.com> wrote:
From: Robert Walters <raw19...@yahoo.com>
Subject: Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
List-Post: users@lists.open-mpi.org
Date: Tuesday, July 6, 2010, 5:41 PM
Thanks for your expeditious responses, Ralph.
Just to confirm with you, I should change openmpi-mca-params.conf to
include:
oob_tcp_port_min_v4 = (My minimum port in the range)
oob_tcp_port_range_v4 = (My port range)
btl_tcp_port_min_v4 = (My minimum port in the range)
btl_tcp_port_range_v4 = (My port range)
correct?
Also, for a cluster of around 32-64 processes (8 processors per node), how wide
of a range will I require? I've noticed some entries in
the mailing list suggesting you need a few to get started and then it opens as
necessary. Will I be safe with 20 or should I go for 100?
Thanks again for all of your help!
--- On Tue, 7/6/10, Ralph Castain <r...@open-mpi.org> wrote:
From:
Ralph Castain <r...@open-mpi.org>
Subject: Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
List-Post: users@lists.open-mpi.org
Date: Tuesday, July 6, 2010, 5:31 PM
Problem isn't with ssh - the problem is that the daemons need to open a TCP
connection back to the machine where mpirun is running. If the firewall blocks
that connection, then we can't run.
If you can get a range of ports opened, then you can specify the ports OMPI
should use for this purpose. If the sysadmin won't allow even that, then you
are pretty well hosed.
On Jul 6, 2010, at 2:23 PM, Robert Walters wrote:
Yes, there is a system firewall. I don't think the sysadmin will
allow it to go disabled. Each Linux machine
has the built-in RHEL firewall. SSH is enabled through the firewall though.
--- On Tue, 7/6/10, Ralph Castain <r...@open-mpi.org> wrote:
From: Ralph Castain <r...@open-mpi.org>
Subject: Re: [OMPI users] OpenMPI Hangs, No Error
To: "Open MPI Users" <us...@open-mpi.org>
List-Post: users@lists.open-mpi.org
Date: Tuesday, July 6, 2010, 4:19 PM
It looks like the remote daemon is starting - is there a firewall in the way?
On Jul 6, 2010, at 2:04 PM, Robert Walters
wrote:
Hello all,
I am using OpenMPI 1.4.2 on RHEL. I have a cluster of AMD Opteron's and right
now I am just working on getting OpenMPI itself up and running. I have a
successful configure and make all install. LD_LIBRARY_PATH and PATH variables
were correctly edited. mpirun -np 8 hello_c successfully works on all machines.
I have setup my two test machines with DSA key pairs that successfully work
with each other.
The problem comes when I initiate my hostfile to attempt to communicate across
machines. The hostfile is setup correctly with <host_name> <slots> <max-slots>.
When running with all verbose options enabled "mpirun --mca plm_base_verbose 99
--debug-daemons --mca btl_base_verbose 30 --mca oob_base_verbose 99 --mca
pml_base_verbose 99 -hostfile hostfile -np 16 hello_c" I receive the following
text
output.
[machine1:03578] mca: base: components_open: Looking for plm components
[machine1:03578] mca: base: components_open: opening plm components
[machine1:03578] mca: base: components_open: found loaded component rsh
[machine1:03578] mca: base: components_open: component rsh has no register
function
[machine1:03578] mca: base: components_open: component rsh open function
successful
[machine1:03578] mca: base: components_open: found loaded component slurm
[machine1:03578] mca: base: components_open: component slurm has no register
function
[machine1:03578] mca: base: components_open: component slurm open function
successful
[machine1:03578] mca:base:select: Auto-selecting plm components
[machine1:03578] mca:base:select:( plm) Querying component [rsh]
[machine1:03578] mca:base:select:( plm) Query of component [rsh] set priority
to 10
[machine1:03578] mca:base:select:( plm) Querying component
[slurm]
[machine1:03578] mca:base:select:( plm) Skipping component [slurm]. Query
failed to return a module
[machine1:03578] mca:base:select:( plm) Selected component [rsh]
[machine1:03578] mca: base: close: component slurm closed
[machine1:03578] mca: base: close: unloading component slurm
[machine1:03578] mca: base: components_open: Looking for oob components
[machine1:03578] mca: base: components_open: opening oob components
[machine1:03578] mca: base: components_open: found loaded component tcp
[machine1:03578] mca: base: components_open: component tcp has no register
function
[machine1:03578] mca: base: components_open: component tcp open function
successful
Daemon was launched on machine2- beginning to initialize
[machine2:01962] mca: base: components_open: Looking for oob components
[machine2:01962] mca: base: components_open: opening oob components
[machine2:01962] mca: base: components_open:
found loaded component tcp
[machine2:01962] mca: base: components_open: component tcp has no register
function
[machine2:01962] mca: base: components_open: component tcp open function
successful
Daemon [[1418,0],1] checking in as pid 1962 on host machine2
Daemon [[1418,0],1] not using static ports
At this point the system hangs indefinitely. While running top on the machine2
terminal, I see several things come up briefly. These items are: sshd (root),
tcsh (myuser), orted (myuser), and mcstransd (root). I was wondering if sshd
needs to be initiated by myuser? It is currently turned off in sshd_config
through UsePAM yes. This was setup by the sysadmin but it can be worked around
if this is necessary.
So in summary, mpirun works on each machine individually, but hangs when
initiated through a hostfile or with the -host flag. ./configure with defaults
and --prefix. LD_LIBRARY_PATH and PATH set up correctly. Any help is
appreciated. Thanks!
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
-----Inline Attachment Follows-----
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
-----Inline Attachment Follows-----
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
-----Inline Attachment Follows-----
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
-----Inline Attachment Follows-----
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
--
David Zhang
University of California, San Diego
-----Inline Attachment Follows-----
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
-----Inline Attachment Follows-----
_______________________________________________
users mailing list
us...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/users
