HP-MPI User's Guide (11th Edition)

Debugging and troubleshooting
Troubleshooting HP-MPI applications
Chapter 6214
[0:hostA] ping-pong 0 bytes ...
0 bytes: 4.24 usec/msg
[1:hostB] ping-pong 0 bytes ...
0 bytes: 4.26 usec/msg
[2:hostC] ping-pong 0 bytes ...
0 bytes: 4.26 usec/msg
[3:hostD] ping-pong 0 bytes ...
0 bytes: 4.24 usec/msg
The table showing SHM/VAPI is printed because of the -prot option
(print protocol) specified in the mpirun command.
It could show any of the following settings:
• VAPI: VAPI on InfiniBand
• UDAPL: uDAPL on InfiniBand
• IBV: IBV on InfiniBand
• PSM: PSM on InfiniBand
• MX: Myrinet MX
• IBAL: on InfiniBand (for Windows only)
• IT: IT-API on InfiniBand
• GM: Myrinet GM2
• ELAN: Quadrics Elan4
• TCP: TCP/IP
• MPID: daemon communication mode
• SHM: shared memory (intra host only)
If the table shows TCP for one or more hosts, it is possible that the host
doesn't have appropriate network drivers installed.
If one or more hosts show considerably worse performance than another,
it can often indicate a bad card or cable.
Other possible reasons for failure could be:
• A connection on the switch is running in 1X mode instead of 4X
mode.
• A switch has degraded a port to SDR (assumes DDR switch, cards).
• A degraded SDR port could be due to using a non-DDR cable.