What are acceptCount, maxConnections and maxThreads in Tomcat HTTP connector configuration?

Question

This is the configuration I'm using

 <Connector port="8080" protocol="HTTP/1.1"
           connectionTimeout="20000"
           redirectPort="8443" acceptCount="1000" maxConnections="500" />

I have read the doc but can't able to understand, please explain with an example if possible, and what is relationship between them.

Answer 1

acceptCount -- The maximum queue length for incoming connection requests when all possible request processing threads are in use. Any requests received when the queue is full will be refused. The default value is 100.

redirectPort -- if this Connector is supporting non-SSL requests, and a request is received for which a matching <security-constraint> requires SSL transport, Catalina will automatically redirect the request to the port number specified here.

MaxConnections -- The maximum number of connections that the server will accept and process at any given time. When this number has been reached, the server will accept, but not process, one further connection.

connectionTimeout -- The number of milliseconds this Connector will wait, after accepting a connection, for the request URI line to be presented

acceptCount is like the line waiting to get into a popular nightclub that is full. (maxConnections) when some people leave maxConnections goes down allowing more people to connect from the acceptCount waiting list. The connection timeout is simply how long it will wait for the request. So you can either make the line longer (acceptCount) or make the nightclub larger (maxConnections)

Redirect port is how/where it handles a redirect due to a security restraint.