This version of the Broker allows sites to start multiple Broker Listener processes in one account. Sites can now also run multiple Listeners in the same UCI-volume, on different IP addresses/CPUs, listening to the same port. If you need to run several Broker Listeners on the same IP address/CPU (e.g., one for a Production account and another for a Test account), they must all be using different ports. For example, if the Listener in the Production account is on port 9200, start another Listener in the Test account on port 9201. Alternatively, you may want to allocate entire ranges of ports for various accounts. If the IP addresses/CPUs are different, then the port can be the same. For example, this means that you can run a Broker Listener on every machine listening on port 9200. This will be important when using DNS for distributing client connections across several machines.
Starting and Stopping Listeners
Starting Listeners via an Option
Obtaining an Available Listener Port (Alpha/VMS Systems Only)
Clients and servers in a medical center must agree on some known "application service ports". We started to use port 9200 for the Broker Listener as a convention but a medical center may fire up several servers, as long as the combination of IP and Port is unique. Clients will attempt to connect to the servers on these established ports. Port 9200 was an example; hospitals could choose anything they have available greater than 1024 (i.e., sockets 1 to 1024 are reserved for standard, well-known services like SMTP, FTP, Telnet, etc.).
It is possible that your port selection may conflict with someone else using the same port on the same machine. However, this should not affect you if you are running on different machines. Someday hospitals may want to query each other. When this happens, hospitals would have to agree on a known service port. In the Internet community, port 25 is mail and everyone is guaranteed to find an SMTP server attached to that port. We may eventually have a service port that all hospitals would have to support to allow for inter-medical center communications.