Hello Pasha,

          As the error was not repeating frequently, I didn't look into the issue from a long time. But now I started to diagnose it:

Initially I tested with ibv_rc_pingpong (Master node to all compute nodes using a for loop). Its working for each of the nodes.

The files generated out of the command "ibdiagnet -v -r -o ." are attached herewith. The ibcheckerrors shows following error message:

# ibcheckerrors
#warn: counter RcvSwRelayErrors = 408   (threshold 100)
Error check on lid 2 (MT47396 Infiniscale-III Mellanox Technologies) port all:  FAILED
#warn: counter RcvSwRelayErrors = 179   (threshold 100)
Error check on lid 2 (MT47396 Infiniscale-III Mellanox Technologies) port 7:  FAILED
# Checked Switch: nodeguid 0x000b8cffff00551b with failure

## Summary: 25 nodes checked, 0 bad nodes found
##          48 ports checked, 1 ports have errors beyond threshold

Are these messages helpful to  find the issue with node-0-2? Can you please help us to diagnose further?

Thanks,
Sangamesh


On Mon, Sep 21, 2009 at 1:36 PM, Pavel Shamis (Pasha) <pashash@gmail.com> wrote:
Sangamesh,

The ib tunings that you added to your command line only delay the problem but doesn't resolve it.
The node-0-2.local gets asynchronous event "IBV_EVENT_PORT_ERROR" and as result
the processes fails to deliver packets to some remote hosts and as result you see bunch of IB errors.

The IBV_EVENT_PORT_ERROR error means that the IB port gone from ACTIVE state do DOWN state.
Or in other words you have problem with your IB networks that cause all these networks errors.
Source cause of such issue maybe some bad cable or some problematic port on switch.

For the IB network debug I propose you use Ibdiaget, it is open source IB network diagnostic tool :
http://linux.die.net/man/1/ibdiagnet
The tool is part of OFED distribution.

Pasha.


Sangamesh B wrote:
Dear all,
      The CPMD application which is compiled with OpenMPI-1.3 (Intel 10.1 compilers) on CentOS-4.5, fails only, when a specific node i.e. node-0-2 is involved. But runs well on other nodes.
       Initially job failed after 5-10 mins (on node-0-2 + some other nodes). After googling error, I added options "-mca btl_openib_ib_min_rnr_timer 25 -mca btl_openib_ib_timeout 20" to mpirun command in the SGE script:
 $ cat cpmdrun.sh
#!/bin/bash
#$ -N cpmd-acw
#$ -S /bin/bash
#$ -cwd
#$ -e err.$JOB_ID.$JOB_NAME
#$ -o out.$JOB_ID.$JOB_NAME
#$ -pe ib 32
unset SGE_ROOT  PP_LIBRARY=/home/user1/cpmdrun/wac/prod/PP
CPMD=/opt/apps/cpmd/3.11/ompi/SOURCE/cpmd311-ompi-mkl.x
MPIRUN=/opt/mpi/openmpi/1.3/intel/bin/mpirun
$MPIRUN -np $NSLOTS -hostfile $TMPDIR/machines -mca btl_openib_ib_min_rnr_timer 25 -mca btl_openib_ib_timeout 20 $CPMD wac_md26.in <http://wac_md26.in>  $PP_LIBRARY > wac_md26.out

After adding these options, job executed for 24+ hours then failed with the same error as earlier. The error is:
 $ cat err.6186.cpmd-acw
--------------------------------------------------------------------------
The OpenFabrics stack has reported a network error event.  Open MPI
will try to continue, but your job may end up failing.
 Local host:        node-0-2.local
 MPI process PID:   11840
 Error number:      10 (IBV_EVENT_PORT_ERR)
This error may indicate connectivity problems within the fabric;
please contact your system administrator.
--------------------------------------------------------------------------
[node-0-2.local:11836] 7 more processes have sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages
[node-0-2.local:11836] 1 more process has sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 7 more processes have sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 1 more process has sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 7 more processes have sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 1 more process has sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 7 more processes have sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 1 more process has sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 7 more processes have sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 1 more process has sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 15 more processes have sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 16 more processes have sent help message help-mpi-btl-openib.txt / of error event
[node-0-2.local:11836] 16 more processes have sent help message help-mpi-btl-openib.txt / of error event
[[718,1],20][btl_openib_component.c:2902:handle_wc] from node-0-22.local to: node-0-2 --------------------------------------------------------------------------
The InfiniBand retry count between two MPI processes has been
exceeded.  "Retry count" is defined in the InfiniBand spec 1.2
(section 12.7.38):
   The total number of times that the sender wishes the receiver to
   retry timeout, packet sequence, etc. errors before posting a
   completion error.
This error typically means that there is something awry within the
InfiniBand fabric itself.  You should note the hosts on which this
error has occurred; it has been observed that rebooting or removing a
particular host from the job can sometimes resolve this issue.
Two MCA parameters can be used to control Open MPI's behavior with
respect to the retry count:
* btl_openib_ib_retry_count - The number of times the sender will
 attempt to retry (defaulted to 7, the maximum value).
* btl_openib_ib_timeout - The local ACK timeout parameter (defaulted
 to 10).  The actual timeout value used is calculated as:
    4.096 microseconds * (2^btl_openib_ib_timeout)
 See the InfiniBand spec 1.2 (section 12.7.34) for more details.
Below is some information about the host that raised the error and the
peer to which it was connected:
 Local host:   node-0-22.local
 Local device: mthca0
 Peer host:    node-0-2
You may need to consult with your system administrator to get this
problem fixed.
--------------------------------------------------------------------------
error polling LP CQ with status RETRY EXCEEDED ERROR status number 12 for wr_id 66384128 opcode 128 qp_idx 3
--------------------------------------------------------------------------
mpirun has exited due to process rank 20 with PID 10425 on
node ibc22 exiting without calling "finalize". This may
have caused other processes in the application to be
terminated by signals sent by mpirun (as reported here).
--------------------------------------------------------------------------
rm: cannot remove `/tmp/6186.1.iblong.q/rsh': No such file or directory
 The openibd service is running fine:
 $ service openibd status
 HCA driver loaded
Configured devices:
ib0
Currently active devices:
ib0
The following OFED modules are loaded:
 rdma_ucm
 ib_sdp
 rdma_cm
 ib_addr
 ib_ipoib
 mlx4_core
 mlx4_ib
 ib_mthca
 ib_uverbs
 ib_umad
 ib_ucm
 ib_sa
 ib_cm
 ib_mad
 ib_core
But still the job is failing after hours of running, that to for a particular node. What's the wrong with node-0-2? How can it be resolved?
 Thanks,
Sangamesh
------------------------------------------------------------------------


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