Poco::HTTPServer setup and diagnostics

I've been trying to configure my HTTPServer and I don't know what has higher priority when passed to c'tor of HTTPServer, the ThreadPool and HTTPServerParams when it comes to setting setMaxThreads.

I'm also having trouble to monitor the queue size since I haven't found any methodes enabling monitoring of queue, and I don't know how to adjust the size and all I can do is use HTTPServerParams::setMaxQueued with guessed value, please advise.