Reconfiguration

The microkernel allows the dynamic reconfiguration of services by permitting the migration of ports. This reconfiguration mechanism requires both servers involved in the reconfiguration to be active at the same time.

The microkernel also offers mechanisms to manage the stability of the system, even in the presence of server failures. The concept of port groups is used to establish the stability of server addresses.

A port group collects several ports together. A server that possesses a port group capability can insert new ports into the group, replacing the terminated ports that were attached to servers.

A client that references a group UI (rather than directly referencing the port attached to a server) can continue to obtain the required services once a terminated port has been replaced in the group. In other words, the lifetime of a group of ports is unlimited, because groups continue to exist even when ports in the group have terminated. Logically, a group needs to contain only a single port, and this only if the server is alive. Thus clients can have stable services as long as their requests for services are made by emitting messages to a group.