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You will see something like below:
Each of the characters in the big square represents a server process. In the screenshot above you can see many "_" characters, which means there are many server processes waiting for a connection . In other words: which means this particular server is not doing much at this moment. When monitoring a web server, you typically refresh the server - status page (press using F5 ) often 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 cloggedbogged 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.
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