The Service Dispatcher works by acting as a central receiver for the TCP ports listed in its configuration. For each defined service, the PMDF Service Dispatcher can create one or more Worker Processes that will actually handle the connections after they've been established. A schematic of a Service Dispatcher and its Worker Processes is shown in Figure 11-1.
Figure 11-1 The Service Dispatcher and Its Worker Processes
In general, when the Service Dispatcher receives a connection for a defined TCP port, it checks its pool of available Worker Processes and chooses the best candidate for the new connection. If no suitable candidate is available and the configuration permits it, the Service Dispatcher can create a new Worker Process to handle this and subsequent connections. The Service Dispatcher can also proactively create a new Worker Process in expectation of future incoming connections. There are several configuration options which can be used to tune the PMDF Service Dispatcher's control of its various services, and in particular, to control the number of Worker Processes and the number of connections each Worker Process handles; see Section 11.1.1 and Section 11.3.