Hello,
I've been experimenting with using ganglios to monitor our machines, and
I've run into a couple small problems.
The first is that /proc/mounts looks like this for us (debian sarge,
2.6.8-2-686-smp). I don't know why it's /dev2 instead of /dev, our /dev
directory is normal, there is no /dev2 in the file system.
station17$ more /proc/mounts
rootfs / rootfs rw 0 0
/dev2/root2 / xfs rw 0 0
proc /proc proc rw,nodiratime 0 0
sysfs /sys sysfs rw 0 0
...
This change allows ganglia to report free disk correctly:
station17$ cvs diff -r ganglia-3-0-1-20051004
srclib/libmetrics/linux/metrics.c
Index: srclib/libmetrics/linux/metrics.c
===================================================================
RCS file: /cvs/ganglia/srclib/libmetrics/linux/metrics.c,v
retrieving revision 1.3
retrieving revision 1.4
diff -r1.3 -r1.4
1188c1188,1189
< if (strncmp(device, "/dev/", 5)) continue;
---
> if (strncmp(device, "/dev/", 5) != 0 &&
> strncmp(device, "/dev2/", 6) != 0) continue;
The second problem: We need daemons we run to put a pid in
/var/run/whatever so they can be watched with monit, etc.
I've added this function to daemon_init.c and I call it from gmond.c and
gmetad.c. I'm not familiar enough with the code to know where this
should go, so I'll offer this instead of a patch:
/**
* @fn void update_pidfile (const char *pname)
* @param argv0 name of this program
*/
void
update_pidfile (const char *argv0)
{
pid_t pid;
static char pidfile[ 256 ];
const char *myname;
FILE *file;
myname = strrchr (argv0, '/');
if (! myname)
myname = argv0;
snprintf (pidfile, sizeof (pidfile), "%s/run/%s.pid", localstatedir,
myname);
/* make sure this program isn't already running. */
file = fopen (pidfile, "r");
if (file)
{
if (fscanf(file, "%d", &pid) == 1 &&
getpgid (pid) > -1)
{
fprintf (stderr, "%s is already running: pid %d\n", myname, pid);
exit (1);
}
close (file);
}
/* write the pid of this process to the pidfile */
umask(0112);
unlink(pidfile);
file = fopen (pidfile, "w");
if (!file)
{
fprintf (stderr, "%s: Error writing pidfile '%s' -- %s\n",
argv0, pidfile, strerror (errno));
exit (1);
}
fprintf (file, "%d\n", (int) getpid());
fclose (file);
}
-seth
