Thanks Russell and Dan, the following are the output that you need.
[root@db03b04 ~]# cat 5174.txt 
restart_syscall(<... resuming interrupted call ...>) = 0
kill(5173, SIG_0)                       = 0
kill(6099, SIG_0)                       = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], SA_RESTORER, 0x7f9827095500}, 8) 
= 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({2, 0}, 0x7f97ebffcb80)       = 0
kill(5173, SIG_0)                       = 0
kill(6099, SIG_0)                       = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], SA_RESTORER, 0x7f9827095500}, 8) 
= 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({2, 0}, 0x7f97ebffcb80)       = 0
kill(5173, SIG_0)                       = 0
kill(6099, SIG_0)                       = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], SA_RESTORER, 0x7f9827095500}, 8) 
= 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({2, 0}, 0x7f97ebffcb80)       = 0
kill(5173, SIG_0)                       = 0
kill(6099, SIG_0)                       = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], SA_RESTORER, 0x7f9827095500}, 8) 
= 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({2, 0}, 0x7f97ebffcb80)       = 0
kill(5173, SIG_0)                       = 0
kill(6099, SIG_0)                       = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
[root@db03b04 ~]# ls -l /proc/5174/exe
lrwxrwxrwx 1 nova nova 0 Dec 19 01:27 /proc/5174/exe -> /usr/bin/python
Thanks,
Guangya
From:
Dan Smith <dansmith(a)redhat.com>
To:
Russell Bryant <rbryant(a)redhat.com>, Perry Myers <pmyers(a)redhat.com>, 
Guang Ya GY Liu/China/IBM@IBMCN, rdo-list <rdo-list(a)redhat.com>
Date:
2013/12/20 02:46
Subject:
Re: [rhos-list] RDO problem
 nova-compute spawns child processes, but not to run multiple
instances
 of nova-compute itself.
 
 Perhaps it's just something inaccurate with the process list where the
 command part didn't get updated... not sure.  In this case 6099 is the
 normal parent nova-compute.  The others are suspect.
 
 Can you grab an strace log from them?  Something like ...
 
 # strace -p 5174 -o 5174.txt 
Also do this, which might be more obvious if it's what we think it is:
 ls -l /proc/5174/exe
--Dan