Apache plugin

Apache is a widely-used web server for a variety of operating systems. For more information, visit http://httpd.apache.org/.

This functionality is only available for agents running on Linux. It is not available on Windows.

Note: You can now collect metrics from your Apache instance using the Ops Agent, the primary and preferred agent for collecting telemetry from your Compute Engine instances. For details, see configuring the Ops Agent for Apache.

Discovery

Even if the Apache plugin is not configured, Cloud Monitoring discovers Apache services running in your Cloud Platform project by:

• Searching instance names for apache

• Checking for ports opened to 80 or 443 via firewall rules

To see the metrics for Apache, do the following:

1. In the navigation panel of the Google Cloud console, select Monitoring, and then select  Dashboards:

   Go to Dashboards

2. Select the Apache HTTP Server dashboard from the list.

Configuring Monitoring to monitor Apache

After you install the Monitoring agent, use the following instructions to configure the Apache plugin on your instances.

Prerequisite

The Apache plugin requires that you enable the mod_status plugin in Apache. Many Apache installations enable this plugin by default. To see if the plugin is enabled on your VM instance, run the following request:

curl http://local-stackdriver-agent.stackdriver.com:80/server-status?auto

If the plugin is enabled, then the output includes lines similar to the following:

 Total Accesses: 2
 Total kBytes: 1
 BusyWorkers: 1
 IdleWorkers: 4

If instead you get a 404 Not Found page, then mod_status is not enabled.

Here are several options to enable the mod_status plugin:

• Download status.conf and place it in the Apache configuration directory on your VM instance, typically in /etc/httpd/conf.d/ or /etc/apache2/conf.d. For more information about enabling the mod_status plugin, refer to the Apache 2.4 or Apache 2.2 documentation:

  (cd /etc/httpd/conf.d/ && sudo curl -O https://raw.githubusercontent.com/Stackdriver/stackdriver-agent-service-configs/master/etc/httpd/conf.d/status.conf)
  

• Append the contents of status.conf to your main Apache configuration file, normally located at either /etc/httpd/conf/httpd.conf or /etc/apache2/apache2.conf on your VM instance.

  Caution: You should only expose the agent's endpoint to localhost through HTTP.

Reload the Apache configuration by running:

• For Debian, Ubuntu, and SLES:

  sudo a2enmod mod_status
  sudo a2enmod mod_access_compat
  sudo service apache2 reload
  

• Other Linux distributions:

  sudo service httpd reload
  

Enabling the Apache monitoring plugin

To enable the Apache monitoring plugin, complete the following steps:

1. On your VM instance, download apache.conf and place it in the directory /etc/stackdriver/collectd.d/:

   (cd /etc/stackdriver/collectd.d/ && sudo curl -O https://raw.githubusercontent.com/Stackdriver/stackdriver-agent-service-configs/master/etc/collectd.d/apache.conf)
   

   If you're not using the default or Google Cloud Observability-provided Apache mod_status configuration, as root, edit apache.conf by following the instructions at the top of the file.

2. Restart the monitoring agent:

   sudo service stackdriver-agent restart
   

For more information on the collectd apache plugin, see Plugin:Apache.

What is monitored

The full list of metrics the Apache plugin monitors is at Agent metrics: apache.