Module mod_status

The Status Module is only available in Apache 1.1 and later.

Function

The Status module allows a server administrator to find out how well their server is performing. A HTML page is presented that gives the current server statistics in an easily readable form. If required this page can be made to automatically refresh (given a compatible browser). Another page gives a simple machine-readable list of the current server state.

The details given are:

The number of children serving requests
The number of idle children
The status of each child, the number of requests that child has performed and the total number of bytes served by the child (*)
A total number of accesses and byte count served (*)
The time the server was started/restarted and the time it has been running for
Averages giving the number of requests per second, the number of bytes served per second and the average number of bytes per request (*)
The current percentage CPU used by each child and in total by Apache (*)
The current hosts and requests being processed (*)

A compile-time option must be used to display the details marked "(*)" as the instrumentation required for obtaining these statistics does not exist within standard Apache.

Enabling Status Support

To enable status reports only for browsers from the foo.com domain add this code to your access.conf configuration file


    <Location /server-status>
    SetHandler server-status
    
    order deny,allow
    deny from all
    allow from .foo.com
    </Location>

You can now access server statistics by using a Web browser to access the page http://your.server.name/server-status

Note that mod_status will only work when you are running Apache in standalone mode and not inetd mode.

Automatic Updates

You can get the status page to update itself automatically if you have a browser that supports "refresh". Access the page http://your.server.name/server-status?refresh=N to refresh the page every N seconds.

Machine Readable Status File

A machine-readable version of the status file is available by accessing the page http://your.server.name/server-status?auto. This is useful when automatically run, see the Perl program in the /support directory of Apache, log_server_status.

Full Instrumentation

To obtain full statistics you must compile Apache with a special directive. On some machines there may be a small performance loss if you do this. Try full statistics and see if you notice any difference. If you do please contact mark@ukweb.com and tell me your configuration.

Do this by adding the following to the AUX_CFLAGS line in the "Configuration" file and then recompiling as usual. AUX_CFLAGS= (something) -DSTATUS

It should be noted that if mod_status is compiled into the server, its handler capability is available in all configuration files, including per-directory files (e.g., .htaccess). This may have security-related ramifications for your site.