Re: [munin-users] vmstat plugin speedup?

[Moses M. <mo...@mo...>]

Nicolai Langfeldt wrote:
> It would also appear that "vmstat 1 1" should do the job - at least on
> Linux.  The vmstat plugin is generic and seems to work on all (or most)
> unixes.

I think the plugin author used 'vmstat 1 2' because the numbers might be 
a little off if vmstat on an old or shifty Unix machine was called in 
the middle between two seconds.  In my opinion being off by one isn't 
that big of a deal.  Oh, unless it'd the difference between 1 and 0 for 
procs 'b' (sleep.value).

Reading vmstat's man page, it says the number for procs 'r' "doesn't 
take into account vmstat itself," whereas using /usr/bin/sed on 
/proc/stat would include sed in procs_running.  This would prevent it 
from every going to '0'... but I doubt that's a bad thing.

 > Would you adapt a vmstat plugin for linux based on /proc/stat
> and then e-mail me please?

Here's a simple patch.  Let me know if I made a mistake.


[moomo@hubble plugins]$ diff -u vmstat-1.4 vmstat
--- vmstat-1.4  2007-09-20 14:26:16.000000000 -0400
+++ vmstat      2007-09-20 14:25:03.000000000 -0400
@@ -1,7 +1,7 @@
  #!/bin/sh
  #
  # Plugin to monitor the number of procs in io-sleep and other wait
-# states. Uses `vmstat`.
+# states. Uses `vmstat` or /proc/stat
  #
  # Parameters:
  #
@@ -9,6 +9,9 @@
  #      autoconf (optional - used by munin-config)
  #
  # $Log$
+# Revision 1.5  2007/09/20 14:19:14  moomo
+# Uses faster method if on a linux machine.
+#
  # Revision 1.4  2004/05/20 13:57:12  jimmyo
  # Set categories to some of the plugins.
  #
@@ -39,7 +42,7 @@


  if [ "$1" = "autoconf" ]; then
-       if ( vmstat 1 1 >/dev/null 2>&1 ); then
+       if ( grep procs_ /proc/stat >/dev/null 2>&1 ) || ( vmstat 1 1 
 >/dev/null 2>&1 ); then
                 echo yes
                 exit 0
         else
@@ -65,7 +67,11 @@
         echo 'sleep.label I/O sleep'
         echo 'sleep.type GAUGE'
         echo 'sleep.max 500000'
         exit 0
  fi

-vmstat 1 2 | awk '{wait = $1; sleep = $2} END { print "wait.value " 
wait "\nsleep.value " sleep }'
+if [ -e /proc/stat ]; then
+       sed '/procs_/!d; s/procs_running/wait.value/; 
s/procs_blocked/sleep.value/' < /proc/stat
+else
+       vmstat 1 2 | awk '{wait = $1; sleep = $2} END { print 
"wait.value " wait "\nsleep.value " sleep }'
+fi

[moomo@hubble plugins]$ _