The Service Dispatcher is a single resident process which starts and shuts down Worker Processes for various services as needed. The Service Dispatcher process can be started with the command

pmdf startup dispatcher

To shut down the Service Dispatcher, use the command

pmdf shutdown dispatcher

What happens with the Worker Processes when the Service Dispatcher is shut down depends upon the underlying TCP/IP package.

For instance, on OpenVMS with Multinet as the TCP/IP package shutting down the Service Dispatcher will not terminate any currently active connections served by any Worker Processes. Rather, the command requests that the Service Dispatcher itself terminate, meaning that new connections will no longer be accepted and then assigned to Worker Processes, and that Worker Processes will automatically terminate as they finish previously assigned tasks and become idle.

On OpenVMS with UCX as the TCP/IP package however, shutting down the Service Dispatcher will also cause the Worker Processes to immediately abort their connections.

If you modify your PMDF configuration or options that apply to the Service Dispatcher, you must restart the Service Dispatcher so that the new configuration or options will take effect. Use the command

pmdf restart dispatcher

Restarting the Service Dispatcher has the effect of shutting down the currently running Service Dispatcher and then immediately starting a new one.

Individual services can be restarted only on OpenVMS or UNIX platforms. Use the command

pmdf restart service-name

where service-name is a service defined in the Service Dispatcher configuration file when the Service Dispatcher was started; for instance, when using the sample Service Dispatcher configuration file, SMTP, POP3, or IMAP (OpenVMS) or smtp, pop3, or imap (UNIX). These commands signal the Service Dispatcher to restart only that component that was specified.

When receiving a command to restart a particular server, the Service Dispatcher first shuts down that service and then immediately starts a new service (re-reading the Service Dispatcher configuration file), creating new Worker Processes as requested.

Individual services can be shut down only on OpenVMS and UNIX platforms. Use the command

pmdf shutdown service-name

where service-name is a service defined in the Service Dispatcher configuration file when the Service Dispatcher was started.

When receiving a command to shut down a particular service, the Service Dispatcher stops accepting new connections for that service and terminates the Worker Processes for that service when they become idle.