RadixHosting
New member
Here's an interesting script I wrote. It basically keep an eye on Apache processes. I've had some problems where Apache suddenly started to consume a lot of memory causing the server load to increase which eventually results in a server crash. 
Anyway it took me some time to figure out what was causing this, so in meanwhile I wrote a script which just restarts Apache before it can do any damage. Prevents downtimes, etc. Hope you like it.
It's written for Apache 1.3 running on cPanel servers, but you can easilly modify it for your own server.
Anyway it took me some time to figure out what was causing this, so in meanwhile I wrote a script which just restarts Apache before it can do any damage. Prevents downtimes, etc. Hope you like it.It's written for Apache 1.3 running on cPanel servers, but you can easilly modify it for your own server.
Code:
#!/bin/bash
# +----------------------------------------------------------------------------
# | chkApache.sh
# | Written for [url]www.radixhosting.com[/url]
# |
# | - Performs a basic scan to check the Apache load
# | - Forcefully restarts Apache if necessary
# | - Sends a report to the system administrator if actions taken
# +----------------------------------------------------------------------------
###############################################################################
# *** START OF CONFIGURATION SETTINGS ***
###############################################################################
# The delay between integrity checks
DELAY=3s
# Minimum server load (5 min. average) for the script to run (integer value)
MIN_LOAD=4
# Maximum % CPU all httpd processes are allowed to use
MAX_CPU=90
# Maximum % memory all httpd processes are allowed to use
MAX_MEM=110
# Kill all httpd processes and restart Apache when a limit has been reached
RESTART_HTTPD=1
# Send a report to the system administrator when a limit has been reached
SEND_REPORT=1
# System administrator to send reports to
ADMIN_MAIL=root
###############################################################################
# *** END OF CONFIGURATION SETTINGS ***
###############################################################################
while [ 1 ]
do
if [ `cat /proc/loadavg | gawk -F "." '{ print $1 }'` -ge $MIN_LOAD ]
then
KILL=0
echo "The minimum server load has been reached, performing Apache integrity scan..."
read REACHED_CPU CUR_CPU < <(ps aux | grep httpd | grep -v grep | gawk -vlimit=$MAX_CPU '{ total+=$3 } END { if (total>limit) { print 1, total } else { print 0, total } }')
if [ $REACHED_CPU -eq 1 ]
then
echo "The CPU limit has been reached. Apache is using $CUR_CPU (limit: $MAX_CPU)."
KILL=1
else
echo "The CPU limit has NOT been reached. Apache is using $CUR_CPU (limit: $MAX_CPU)."
fi
read REACHED_MEM CUR_MEM < <(ps aux | grep httpd | grep -v grep | gawk -vlimit=$MAX_MEM '{ total+=$4 } END { if (total>limit) { print 1, total } else { print 0, total } }')
if [ $REACHED_MEM -eq 1 ]
then
echo "The memory limit has been reached. Apache is using $CUR_MEM (limit: $MAX_MEM)."
KILL=1
else
echo "The memory limit has NOT been reached. Apache is using $CUR_MEM (limit: $MAX_MEM)."
fi
if [ $KILL -eq 1 ]
then
if [ $SEND_REPORT -eq 1 ]
then
echo "Sending report to the system administrator..."
mail -s "chkApache.sh alert on `hostname`" $ADMIN_MAIL <<< cat <<EOF
******************************************************
chkApache.sh report
******************************************************
*** APACHE LOAD
CPU usage: $CUR_CPU (limit: $MAX_CPU)
Mem usage: $CUR_MEM (limit: $MAX_MEM)
*** CURRENT LOAD
`cat /proc/loadavg`
*** MEMORY STATISTICS
`free -m`
*** APACHE STATUS REPORT
`lynx -dump http://127.0.0.1/whm-server-status`
*** TOP PROCESSES LIST
`top -b -n 1`
*** NETSTAT HTTP CONNECTIONS
`netstat -a | grep :http`
*** APACHE PROCESSES
`ps aux | grep httpd`
******************************************************
EOF
fi
if [ $RESTART_HTTPD -eq 1 ]
then
echo "Trying to kill all httpd processes..."
COUNTER=0
while [ $COUNTER -lt 50 ]; do
killall -15 httpd
killall -9 httpd
if [ $? -ne 0 ]
then
echo "All httpd processes were killed."
COUNTER=100
else
COUNTER=`expr $COUNTER + 1`
fi
done
if [ $COUNTER -ne 100 ]
then
echo "WARNING: Failed to kill all httpd processes!"
fi
echo "Restarting httpd..."
service httpd startssl
echo "Done."
sleep 5s
fi
fi
else
echo "The minimum server load has not been reached."
fi
sleep $DELAY
done
