error while trying to run MPI program with username - c

Question

When I run program via:
myshell$] mpirun --hosts localhost,192.168.1.4 ./a.out
the program executes successfully. Now when I try to run:
myshell$] mpirun --hosts localhost,myac#192.168.1.4 ./a.out
openssh prompts for password. I get:
Fatal error in MPI_Init: Other MPI error, error stack:
MPIR_Init_thread(433)..............:
MPID_Init(176).....................: channel initialization failed
MPIDI_CH3_Init(70).................:
MPID_nem_init(286).................:
MPID_nem_tcp_init(108).............:
MPID_nem_tcp_get_business_card(354):
MPID_nem_tcp_init(313).............: gethostbyname failed, myac#192.168.1.4 (errno 1)
===================================================================================
= BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
= EXIT CODE: 1
= CLEANING UP REMAINING PROCESSES
= YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
===================================================================================
[proxy:0:0#myac] HYD_pmcd_pmip_control_cmd_cb (./pm/pmiserv/pmip_cb.c:886): assert (!closed) failed
[proxy:0:0#myac] HYDT_dmxu_poll_wait_for_event (./tools/demux/demux_poll.c:77): callback returned error status
[proxy:0:0#myac] main (./pm/pmiserv/pmip.c:206): demux engine error waiting for event
[mpiexec#myac] HYDT_bscu_wait_for_completion (./tools/bootstrap/utils/bscu_wait.c:76): one of the processes terminated badly; aborting
[mpiexec#myac] HYDT_bsci_wait_for_completion (./tools/bootstrap/src/bsci_wait.c:23): launcher returned error waiting for completion
[mpiexec#myac] HYD_pmci_wait_for_completion (./pm/pmiserv/pmiserv_pmci.c:217): launcher returned error waiting for completion
[mpiexec#myac] main (./ui/mpich/mpiexec.c:331): process manager error waiting for completion
Why am I getting error when I am providing the username?

Answer 1

You could try specifying a username in your ssh config file (http://www.cyberciti.biz/faq/create-ssh-config-file-on-linux-unix/) instead of on the mpirun command line. That way perhaps mpirun would not be confused by the extra username part, which as far as I can see from the documentation it does not support. But ssh could, behind the scenes, use the username you specify in your ssh config file. And of course you'll want to set up SSH keys so you don't have to type a password.

Answer 2

I don't believe MPICH supports providing usernames in the --hosts value on the command line. You should try the host file based method described on the wiki. http://wiki.mpich.org/mpich/index.php/Using_the_Hydra_Process_Manager#Using_Hydra_on_Machines_with_Different_User_Names
For example:
shell$ cat hosts
donner user=foo
foo user=bar
shakey user=bar
terra user=foo