Forum Discussion

Luis_Araujo_560's avatar
Luis_Araujo_560
Icon for Nimbostratus rankNimbostratus
Sep 06, 2012

External monitor snmp - Member UP/DOWN

This external monitor uses the threshold of CPU and Memory for classify the pool member as available or down. I calculated the results of snmp to have the desired percentage.

 

Follow the steps:

 

 

1. Create the arquive called "script_snmp" in "/config/monitors/" and copy the script below:

 

 

!/bin/sh

 

 

IPv6/IPv4 compatibility prefix (LTM passes addresses in IPv6 format)

 

 

IP=`echo ${1} | sed 's/::ffff://'`

 

PIDFILE="/var/run/`basename ${0}`.${IP}_${PORT}.pid"

 

 

kill of the last instance of this monitor if hung and log current pid

 

if [ -f $PIDFILE ]

 

then

 

kill -9 `cat $PIDFILE` > /dev/null 2>&1

 

fi

 

echo "$$" > $PIDFILE

 

 

send request & check for expected response

 

snmpwalk -v 2c -c community ${IP} .1.3.6.1.4.1.2021.4.5.0 > /var/tmp/monitor/mem_size_${IP}.log

 

snmpwalk -v 2c -c community ${IP} .1.3.6.1.4.1.2021.4.6.0 > /var/tmp/monitor/mem_avail_${IP}.log

 

snmpwalk -v 2c -c community ${IP} .1.3.6.1.4.1.2021.11.11 > /var/tmp/monitor/cpu_${IP}.log

 

mark node UP if expected response was received

 

size=`cat /var/tmp/monitor/mem_size_${IP}.log | cut -f4 -d" "`

 

avail=`cat /var/tmp/monitor/mem_avail_${IP}.log | cut -f4 -d" "`

 

expr $avail \* 100 / $size > /var/tmp/monitor/percentage_${IP}

 

memory=`cat /var/tmp/monitor/percentage_${IP}`

 

cpu=`cat /var/tmp/monitor/cpu_${IP}.log | cut -f4 -d" "`

 

 

if [ "$memory" -le "85" ]; then

 

if [ "$cpu" -ge "20" ]; then

 

echo "UP"

 

rm -f $PIDFILE

 

elif [ "$DEBUG" -eq "1" ]; then

 

echo "The threshold CPU has reached for $IP - DOWN" | logger -p local0.debug

 

rm -f $PIDFILE

 

fi

 

else

 

echo "The threshold MEMORY has reached for $IP - DOWN" | logger -p local0.debug

 

rm -f $PIDFILE

 

fi

 

 

2. Give permission by execution: chmod 755 script_snmp;

 

3. Create folder called "monitors" in "/var/tmp";

 

4. In LTM/Monitors, click in "CREATE"

 

5. write the monitor name

 

6. Choice the monitor external type

 

7. Set the runtime

 

8. Set the path of script

 

9. In variable, set the value: DEBUG=1

 

10. Click in "FINISH"

 

11. Set the monitor the Pool

 

 

Feel free to improve the script

 

 

management
monitoring
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Sep 08, 2012
    Hi Luis,

     

     

    That looks great. Thanks for sharing the monitor script.

     

     

    The only change I suggest is to do the PIDFILE removal before echoing anything to standard out, as the script execution will be stopped immediately at this point.

     

     

    If you want, you could add this to the monitoring codeshare:

     

    http://devcentral.f5.com/wiki/AdvDesignConfig.codeshare.ashx

     

     

    Thanks, Aaron
  • Luis_Araujo_560's avatar
    Luis_Araujo_560
    Icon for Nimbostratus rankNimbostratus
    Sep 10, 2012

    Hi Aaron,

     

    Thank for reponse!!!

     

    I insert the PIDFILE in end script because not was functioning the script.

     

    I think that "echo" was classify the pool member as "UP"

     

    You can add thus script in codeshare.

     

     

    Thanks!!!!

     

  • nanbee_109009's avatar
    nanbee_109009
    Icon for Nimbostratus rankNimbostratus
    Oct 17, 2012
    Great script, thanks for sharing.

     

     

    One typo I noticed in step 3, In var/tmp you want to create a folder called monitor not monitors as thats how its written in the script.

     

    "3. Create folder called "monitors" in "/var/tmp"

     

     

    Also in ver 11 you can import the script file via : System - File Management - External Monitor Program File List - Import.

     

    Then you add the external monitor and under External Program choose that script you just imported from the drop down list, add your DEBUG = 1 variable and save.