Script to restart a server automatically if it’s load increases above a limit :
#!/usr/bin/ bash
LOAD=`uptime |awk '{print $NF}'`
LOADCOMP=`echo $LOAD \> 15 |bc -l`
if [ $LOADCOMP -eq 1 ]
then /sbin/shutdown -r 0
fi
Note: Here 15 defines the server load, you can adjust as per your need.
- Write this code in a file (eg. nano restartscript.sh) and paste the code.
- The file should have extension .sh. After saving the script, make it executable by running the following command :
chmod 777 restartscript.sh
- Now we need to add this script to cron which will run every 2 minutes
- Type crontab -e to open the cron input file.
- Enter the following code to run the script we just created
*/2 * * * * cd /path/to/file && sh ./restartscript.sh > /var/log/cronlogfile.log 2>&1
Note :
You need to replace /path/to/file with the path directory you have saved the file.
To check if cron is added successfully run crontab -l to list all the crons.
Now, whenever the specific server load will go beyond the given limit (i.e 10 in our case), the server / VPS will reboot. Though this is a temporary solution if you are facing sudden/abnormal spikes in your server and restarting fixes the same. On a longer run, you need to debug the same and resolve the main issue which causes the load spike.
