- 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
Monitoring Apache with SNMP
There are a couple of open-source modules that add Simple Network Management Protocol (SNMP) capabilities to the Apache web server. This protocol is commonly used to manage network servers and equipment from a central console such as HP OpenView and Tivoli. With this module, you can easily monitor Apache performance in real time, including server uptime, load average, number of errors in a certain period of time, number of bytes and requests served, and many other metrics. The SNMP modules can also generate alarms when a certain threshold or error condition is met, such as a sudden increase in the number of simultaneous client connections.
For Apache 1.3, you can use mod_snmp, which can be found at http://www.mod-snmp.com/ and supports SNMP version 1 and 2. It requires patching of the Apache core.
For Apache 2, you can use a similar module called mod_apache_snmp. It can be found at http://modapachesnmp.sourceforge.net/. This module supports versions 1, 2, and 3 of the SNMP protocol and can be compiled as a DSO, without the need to patch Apache.