Re: [BProc] getpwuid and getgrgid bombing

[Erik A. H. <er...@he...>]

On Wed, May 29, 2002 at 12:39:53PM -0400, Daniel Widyono wrote:
> Any ideas?  How do I go about debugging bpsh calls in general?  strace output
> on master doesn't seem promising.  strace -f gives:

   What does the environment look like?  Are you using a Clustermatic
   or Scyld-like environment?  Specifically, I'm wondering if you're
   using the normal NSS stuff for lookups or using beonss/bproc.
   beonss is a bit quirky when you ask for user names.

As far as strace goes, you can take two routes with bpsh.  Both
require BProc version 3 or later.

strace bpsh -N 0 command

This turns off ALL I/O forwarding.  This means that you don't get to
see output but bpsh *will* exec the command directly so strace will be
attached to the right process.

Another alternative is to use the undocumented "-S" flag.  This stops
the child process before doing bproc_execmove.  That gives you a
window to attach strace to the child before it runs.  For example:

$ bpsh 0 -S uptime
<it hangs here>

In another window:
$ ps xf | grep uptime
20172 pts/10   S      0:00 grep uptime
20169 pts/9    S      0:00 bpsh 0 -S uptime
20170 pts/9    T      0:00  \_ bpsh 0 -S uptime
$ strace -p 20170
--- SIGSTOP (Stopped (signal)) ---
SYS_291(0x304, 0, 0x11ffff110, 0x11ffff8d0, 0x11ffff8e0) = 0
SYS_0(0x304, 0, 0x11ffff110, 0, 0x11ffff8e0) = -1 ERRNO_339 (errno 339)
SYS_0(0x11ffff2b8, 0x20000005870, 0, 0, 0x2) = 17
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
.... watch uptime run to completion...


- Erik
-- 
Erik Arjan Hendriks          Printed On 100 Percent Recycled Electrons
er...@he...                   Contents may settle during shipment