Apache Server Status

The Apache HTTP Server can be configured to allow access to its "server-status" monitoring tool. This tool allows you to see what server processes are active and what they are doing. It also allows you to monitor the URLs that are being served and the time it takes to serve them. Your system administrator can configure Apache to allow access to the Server Status tool for you. It is wise to restrict access to it using a  username/password combination. This can be performed on both the backend and frontend server(s). Usually the backend server is preferred because it is shielded  If you are working in a clustered server environment, each of the servers can be outfitted with the Server Status tool.

What it Looks Like

When enabled, the Server Status tool can be accessed at the following URL:

You will see something like below:

In the screenshot above you can see many "_" characters, which means there are many server processes waiting for a connection which means this particular server is not doing much at this moment. When monitoring a web server, you typically refresh the server status page using F5 in rapid succession. This allows you to see what the server is doing in real time.

Troubleshooting

If all available slots display characters like "K" or "W", this indicates a problem — the server is getting bogged down. The list of requests give you a hint where to start looking for the source of the problem. Most likely some slow URL is popular and gets requested often. From there you can devise strategies to avoid that URL from (a) being slow or (b) being requested so often. Either strategy will relieve some of the load on your server.