Max Pending Count specifies the maximum number of pending connections on the listen socket. Adjust Max Pending Count only when there is a heavy load on the system. For low to medium loads, the default will be acceptable.
After observing system behavior, change the value accordingly, otherwise the server will start dropping connections. Connections that time out on a listen socket whose backlog queue is full will fail. If Max Pending Count is close to the limit, increase the maximum connection queue size to avoid dropping connections under heavy load.