Bandwidth monitoring done right 🙂
If available on your devices, you should always use sFlow for bandwidth measurement.
The sFlow deamon is started with the following script.
#!/bin/bash
# init file for sflow
# Rob Hassing - 05/03/12
# INIT INFO.
# chkconfig: - 49 51
# description: Sflowtool
#
# processname: /usr/bin/sflowtool
# pidfile: /var/run/sflowtool.pid
### BEGIN INIT INFO
### END INIT INFO
# source function library
. /etc/init.d/functions
OPTIONS="-4 | /usr/share/sflowtool/scripts/sflowRRDLoad"
RETVAL=0
prog="sflowtool"
start() {
echo -n $"Starting $prog: "
daemon /usr/bin/sflowtool $OPTIONS &
RETVAL=$?
echo
touch /var/lock/subsys/sflowtool
return $RETVAL
}
stop() {
echo -n $"Stopping $prog: "
killproc /usr/bin/sflowtool 2>/dev/null
RETVAL=$?
echo
rm -f /var/lock/subsys/sflowtool
if test -f /var/run/sflowtool.pid ; then
[ $RETVAL -eq 0 ] && rm -f /var/run/sflowtool.pid
fi
return $RETVAL
}
reload(){
echo -n $"Reloading config file: "
killproc sflowtool -HUP
RETVAL=$?
echo
return $RETVAL
}
restart(){
stop
start
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
restart
;;
reload|force-reload)
reload
;;
status)
status sflowtool
RETVAL=$?
;;
*)
echo $"Usage: $0 {start|stop|status|restart|try-restart|condrestart|reload|force-reload}"
RETVAL=1
esac
exit $RETVAL
The following script can be used to create rrd files through the sFlow daemon (
/usr/share/sflowtool/scripts/sflowRRDLoad) This file is used in the startup script.
#! /usr/bin/perl
# Copyright (c) 2001 InMon Corp. Licensed under the terms of the InMon sFlow licence:
# http://www.inmon.com/technology/sflowlicense.txt
#makes things work when run without install
use lib qw( ../perl-shared/blib/lib ../perl-shared/blib/arch );
#makes programm work AFTER install
use lib qw( /usr/local/rrdtool-1.0.33/lib/perl ../lib/perl /usr/lib64/perl5/vendor_perl/5.8.8/x86_64-linux-thread-multi /usr/lib64/perl5/vendor_perl/5.8.8/x86_64-linux-thread-multi/auto/RRDs );
use vars qw(@ISA $loaded);
use RRDs;
$dataDir="/var/spool/sflow/rrd";
$dataDir2="/var/spool/sflow/discards";
while(<>) {
  ($key, $value) = split /[\t =]+/, $_;
  chomp $key;
  chomp $value;
  if($key eq "unixSecondsUTC") {$t = $value;}
  if($key eq "agent") {$agent = $value;}
  if($key eq "ifIndex") {$ifIndex = $value;}
  if($key eq "ifSpeed") {$ifSpeed = $value;}
  if($key eq "ifInOctets") {$ifInOctets = $value;}
  if($key eq "ifOutOctets") {
    $ifOutOctets = $value;
    $rrd = "$dataDir/$agent-$ifIndex.rrd";
    if(! -e $rrd) {
      RRDs::create ($rrd, "--start",$t-1, "--step",20,
             "DS:bytesIn:COUNTER:120:0:10000000000",
             "DS:bytesOut:COUNTER:120:0:10000000000",
             "RRA:MIN:0.5:1:44640",
             "RRA:MAX:0.5:1:44640",
             "RRA:AVERAGE:0.5:3:525600");
      $ERROR = RRDs::error;
      die "$0: unable to create `$rrd': $ERROR\n" if $ERROR;
    }
    if ($agent!="0.0.0.0"){
    RRDs::update $rrd, "$t:$ifInOctets:$ifOutOctets";
    }
    if ($ERROR = RRDs::error) {
      die "$0: unable to update `$rrd': $ERROR\n";
    }
  }
  if($key eq "unixSecondsUTC") {$t = $value;}
  if($key eq "agent") {$agent = $value;}
  if($key eq "ifIndex") {$ifIndex = $value;}
  if($key eq "ifInErrors") {$ifInErrors = $value;}
  if($key eq "ifOutErrors") {$ifOutErrors = $value;}
  if($key eq "ifInDiscards") {$ifInDiscards = $value;}
  if($key eq "ifOutDiscards") {
    $ifOutDiscards = $value;
    $rrd2 = "$dataDir2/$agent-$ifIndex-discards.rrd";
    if(! -e $rrd2) {
      RRDs::create ($rrd2, "--start",$t-1, "--step",20,
             "DS:DicardsIn:COUNTER:120:0:10000000",
             "DS:ErrorsIn:COUNTER:120:0:10000000",
             "DS:DicardsOut:COUNTER:120:0:10000000",
             "DS:ErrorsOut:COUNTER:120:0:10000000",
             "RRA:AVERAGE:0.5:3:576");
      $ERROR = RRDs::error;
      die "$0: unable to create `$rrd2': $ERROR\n" if $ERROR;
    }
    if ($agent!="0.0.0.0"){
    RRDs::update $rrd2, "$t:$ifInDiscards:$ifInErrors:$ifOutDiscards:$ifOutErrors";
    }
    if ($ERROR = RRDs::error) {
      die "$0: unable to update `$rrd2': $ERROR\n";
    }
  }
}
The following script could be used to find out your utilization for the interfaces. This script can only be used if data collected by the sFlow daemon is already available.
OK=0
WARNING=1
CRITICAL=2
ERROR=4
ip=$1
port=$2
if [ -z "$ip" -o -z "$port" ] || [ -n "$c" -a -z "$w" ]
then
    echo usage: "$0 <ipaddress> <port number> [<linewidt> [<critical> <warning>]]"
    exit $ERROR
fi
lw=$3
c=$4
w=$5
c=${c:-30}
w=${w:-25}
lw=${lw:=1G}
dir=/var/spool/sflow/rrd
case $lw in
1M)
    lw=1000000
    ;;
10M)
    lw=10000000
    ;;
100M)
    lw=100000000
    ;;
1G)
    lw=1000000000
    ;;
10G)
    lw=10000000000
    ;;
100G)
    lw=100000000000
    ;;
*)
    echo linewidth value incorrect, mustby 1M, 10M, 100M, 1G, 10G or 100G
    exit $ERROR
    ;;
esac
file=$dir/$ip-$port.rrd
if ! data=$(rrdtool fetch $file AVERAGE -s -360 -e -120Â | tail -5)
then
    echo Could not fetch rrd data from $file
    exit $UNKNOWN
fi
set $data
while [ -n "$1" ]
do
    t=$1
    in=$2
    out=$3
    shift 3
#Â Â Â Â l=${l#*: }
#Â Â Â Â in=${l%% *}
    ine=${in##*e+}
    inm=${in%%e*}
    inm=$(echo "$inm * 10 ^ $ine" | bc)
    in=${inm%%.*}
    (( sin += in ))
    oute=${out##*e+}
    outm=${out%%e*}
    outm=$(echo "$outm * 10 ^ $oute" | bc)
    out=${outm%%.*}
    (( sout += out ))
#echo $sin $sout
done
#echo $sin $sout
((ain = sin * 8 / 5 ))
((aout = sout * 8 / 5 ))
((pin = ain * 100 / lw))
((pout = aout * 100 / lw))
if [ $pin -ge $c -o $pout -ge $c ]
then
echo "CRITICAL: RX: $pin% TX: $pout%"
    exit $CRITICAL
fi
if [ $pin -ge $w -o $pout -ge $w ]
then
echo "WARNING: RX: $pin% TX: $pout%"
    exit $WARNING
fi
echo "OK: RX: $pin% TX: $pout%"
exit $OK