Recently, my blog always shutdown, it use centos6.2+apache2.2+mysql5.5+php5.3. I have raised MaxClients in httpd.conf, but less useful.
So is it possible to write a shell script (Run with crontab every 10 minutes), to read the httpd/error_log, if the last message preg_match sending a SIGTERM do restart apache automatically?
Parsing the log files can be pretty tricky. Rather than try to do that, you'd probably be better off using a script such as this one which can run from a crontab entry. This script will attempt to access the server, if it's unsuccessful then it will restart Apache.
Source of script: bash script to restart Apache automatically
#!/bin/sh # Script that checks whether apache is still up, and if not: # - e-mail the last bit of log files # - kick some life back into it # -- Thomas, 20050606 PATH=/bin:/usr/bin THEDIR=/tmp/apache-watchdog [email protected] mkdir -p $THEDIR if ( wget --timeout=30 -q -P $THEDIR http://localhost/robots.txt ) then # we are up touch ~/.apache-was-up else # down! but if it was down already, don't keep spamming if [[ -f ~/.apache-was-up ]] then # write a nice e-mail echo -n "apache crashed at " > $THEDIR/mail date >> $THEDIR/mail echo >> $THEDIR/mail echo "Access log:" >> $THEDIR/mail tail -n 30 /var/log/apache2_access/current >> $THEDIR/mail echo >> $THEDIR/mail echo "Error log:" >> $THEDIR/mail tail -n 30 /var/log/apache2_error/current >> $THEDIR/mail echo >> $THEDIR/mail # kick apache echo "Now kicking apache..." >> $THEDIR/mail /etc/init.d/apache2 stop >> $THEDIR/mail 2>&1 killall -9 apache2 >> $THEDIR/mail 2>&1 /etc/init.d/apache2 start >> $THEDIR/mail 2>&1 # send the mail echo >> $THEDIR/mail echo "Good luck troubleshooting!" >> $THEDIR/mail mail -s "apache-watchdog: apache crashed" $EMAIL < $THEDIR/mail rm ~/.apache-was-up fi fi rm -rf $THEDIR The paths to the stop/start scripts will need to be adjusted accordingly based on where your distro has installed Apache. Lines like this one:
/etc/init.d/apache2 start >> $THEDIR/mail 2>&1 If you're on CentOS will be like this:
/etc/init.d/httpd start >> $THEDIR/mail 2>&1 The same goes with the killlall lines. The name of the executable on CentOS is httpd.
This cron will need to be run as root so that it has the appropriate permissions to stop/start Apache.
