Port Registry in ATG servers

One of the more confusing aspects of server-side applications is the number of TCP servers that might
start up. The standard configuration for an ATG application, for example, starts between four and six
separate TCP servers. To help organize these servers, ATG includes a service called
atg.service.portregistry.PortRegistry that keeps track of which services started servers on
which ports. The PortRegistry has a Nucleus address of /atg/dynamo/server/PortRegistry. This
component’s page in the Component Browser lists which services are using which ports.
The PortRegistry does not automatically find server components. Instead, individual server
components are expected to register themselves with the PortRegistry.
Every subclass of RequestServer already has the ability to automatically register with a PortRegistry
when it starts up. To do this, the component must be configured with a property that points to the
PortRegistry.
For example, the HTTP server might be configured like this:

portRegistry=/atg/dynamo/server/PortRegistry

If you create a server component that does not extend RequestServer, your component should define a
portRegistry property to be set in the configuration file. When it starts, it should register itself with the
PortRegistry like this:

if (getPortRegistry () != null) { 
  getPortRegistry ().addEntry (getPort (), getAbsoluteName ()); 
}

Note: This assumes that port is available as a property. The getAbsoluteName method is available only
if your server component extends atg.nucleus.GenericService. If you extend GenericService, this
code most likely appears inside your doStartService method. Also, your doStopService method
should include the following code:

if (getPortRegistry () != null) { 
  getPortRegistry ().removeEntry (getPort (), getAbsoluteName ()); 
}