Re: 19990727: ldmadmin isrunning

Jim,

Thanks for finding that bug, I'll make it more robust.

Robb...



On Tue, 27 Jul 1999, Unidata Support wrote:

> 
> ------- Forwarded Message
> 
> >To: address@hidden
> >cc: John Murphy <address@hidden>
> >From: Jim Cowie <address@hidden>
> >Subject: ldmadmin isrunning
> >Organization: .
> >Keywords: 199907271507.JAA28346
> 
> 
> Found an obscure bug in ldmadmin. (5.0.6 and greater) The command 
> 'ldmadmin isrunning' can return 0 (indicating that it is running)
> when it is actually not running and an old ldmd.pid file exists with
> a process ID that matches a non-ldm process. Here is the scenario
> where I've seen this happen several times.
> 
> LDM starts soon after a reboot and thus gets a fairly low (ie; small)
> process ID. Sometime later the system crashes or reboots suddenly.
> The ldmd.pid file still exists. The command 'ldmadmin isrunning'
> is executed, it gets the process ID from the ldmd.pid file, then
> checks that that process is running. But that process is not an LDM
> process, it's something totally unrelated that was started upon boot
> up depending on the vaguaries of the system. ldmadmin isrunning then
> returns saying the LDM is running when it's not.
> 
> For the time being, I modified our version of the check_running()
> subroutine to change the command that looks for the process from the
> ldmd.pid file. I changed it to grep for the string "rpc.ldmd" to confirm
> that it's actually an LDM that that process ID belongs to.
> 
> -jim
> 
> 
> 
> sub check_running {
> 
> my($pid_num, $ps_cmd);
> 
> $pid_num = getPid() ;
> 
> return 1 if( $pid_num == -1 ) ;
> 
> if (($os eq "SunOS" && $version =~ /^4/) || $os eq "Linux" ) {
>     $ps_cmd = "ps $pid_num | grep rpc.ldmd | grep -v grep";
> 
> } else {
>     $ps_cmd = "ps -p $pid_num | grep rpc.ldmd | grep -v grep";
> }
> 
> `$ps_cmd`;
> 
> if ($?) {
>     return 1;
> }
> else {
>     return 0;
> }
> }
> 
> 
> -- 
> Jim Cowie                             Software Engineer
> WITI Corporation                      address@hidden
> 3300 Mitchell Lane 
> Boulder, CO 80301                     (303) 497-8584
> 
> 
> ------- End of Forwarded Message
> 

===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================