Web Server automatically configures the connection queue size based on the number of available file descriptors in the system. The connection queue size on a system is determined by the sum total of thread-pool/max-threads element, thread-pool/queue-size element and keep-alive/max-connections element in the server.xml file.
For more information about the server.xml file, see the Administrator's Configuration File Reference.
In certain cases, the server's chosen defaults leads to larger memory footprint than what is required to run your applications. If the server selected defaults does not suit your needs, the memory usage of the server can be changed by specifying the values in server.xml. The thread-pool/max-threads is greater of 128 or the number of processors in the system unless explicitly specified in server.xml. The thread-pool/queue-size can be obtained from perfdump by examining the Connection Queue Information. For more information, see Connection Queue Information. The keep-alive/max-connections can be obtained from Keep-Alive Information and Keep-Alive Count. Logging at level fine will print these values in the error log file.