- Introduction to Logging in Apache
- Default Apache Log Files
- Creating Log Formats
- Creating a Custom Log File
- Redirecting Logs to an External Program
- Logging Requests Conditionally
- Monitoring Who Is Linking to Your Website
- Monitoring Apache with mod_status
- Monitoring Apache with SNMP
- Analyzing Your Logs with Open-source Tools
- Monitoring Your Logs in Real Time
- Logging Requests to a Database
- Rotating and Archiving Logs
- Controlling IP Address Resolution
- Processing Logged IP Addresses
- Restarting Apache Automatically If It Fails
- Merging and Splitting Log Files
- Keeping Separate Logs for Each Virtual Host
- Common Log Entries
This chapter is from the book
This chapter is from the book
This chapter is from the book
Restarting Apache Automatically If It Fails
#!/bin/bash if [ `ps -waux | grep -v grep | grep -c httpd` -lt 1 ]; then apachectl restart; fi
If you install Apache on Windows as a service, it can be automatically restarted by the service manager if it crashes.
In Unix, you can implement this functionality with a watchdog script. A watchdog monitors the status of another program, and if the program crashes or stops for any reason, the watchdog starts it again. The example shows a simple Linux script that will monitor the system process list to ensure that an httpd process exists, and will restart httpd if it crashes. To use it, you will need to give it executable permissions and add it to your cron configuration so it can be run at predefined intervals.
If you are running Solaris, use ps -ef instead of ps - waux.
You can find a more sophisticated watchdog script that will send email when the server is down, and can watch specific httpd process ids, at the following URL: http://perl.apache.org/docs/general/control/control.html.
Most Linux distributions also include their own generic watchdog scripts that can be adapted to work with Apache.