You can tune the maximum number of connections that the server allows to wait at one time before closing the oldest connection in the Admin Console by editing the Maximum Connections field on the configuration's Performance tab ⇒ HTTP tab, under Keep Alive Settings. The default is based on the number of available file descriptors in the system. In the command-line interface, use the max-connections property in the wadm set-keep-alive-prop command.
The number of connections specified by the maximum connections setting is divided equally among the keep-alive threads. If the maximum connections setting is not equally divisible by the keep-alive threads setting, the server might allow slightly more than the maximum number of simultaneous keep-alive connections.