Generally speaking, Remoting services are defined on endpoints in the following way by specifying a channel name and an OpenListener:

        try {
            registration = endpoint.registerService(CHANNEL_NAME, channelOpenListener, this.channelCreationOptions);
        } catch (ServiceRegistrationException e) {
            throw new StartException(e);
        }

Once the service has been registered, it can in general be used atop any connection from the client to any Remoting connector by calling from the client:

        IoFuture<Channel> futureChannel = connection.openChannel(CHANNEL_NAME, OptionMap.EMPTY);

Sometimes we want to restrict the connectors that services can be created on.

We want to introduce a version of registerService which allows being able to restrict the set of connectors we may use the service on, by way of a validation predicate on the Connection:

      Predicate<Connection> validationPredicate = {some predicate defined in terms of connection instance}
        try {
            registration = endpoint.registerService(CHANNEL_NAME, channelOpenListener, this.channelCreationOptions, validationPredicate);
        } catch (ServiceRegistrationException e) {
            throw new StartException(e);
        }

For example, we may wish prevent service requests atop of a connection on the connector listening on port 1234.

When we try to create a service Channel on a connection for which the validationPredicate evaluates to false, the connection is refused and the client receives a ServiceOpenException with message "Service refused".