Planning and Configuring HP DCE 1.8

Chapter 5 105
Configuring HP DCE Cells
Integrating DCE Services with MC/ServiceGuard
Integrating DCE Services with
MC/ServiceGuard
MC/ServiceGuard is a Series 800 product that was introduced at HP-UX
10.0. MC/ServiceGuard provides an environment in which, if anode fails,
services (applications) can be up and running again on another node very
quickly.
This section provides background information on MC/ServiceGuard, and
explains detailed planning and configuration steps necessary to utilize
MC/ServiceGuard to increase the availability of the DCE core services.
The process and considerations provided here are also easily extended to
DCE-based application servers.
Readers of this section should already have a license for the
MC/ServiceGuard product and be familiar with the contents of
Managing MC/ServiceGuard (B3936-90003), which describes the
features and capabilities of MC/ServiceGuard and provides a general
conceptual framework for planning, configuring, and operating an
MC/ServiceGuard cluster.
Background
The DCE infrastructure depends on three core services, all of which are
necessary for the proper operation of a DCE Cell: the Security Service,
the Naming Service, and the Time Service. In a properly configured DCE
cell, each of these services is distributed and replicated, in order to
increase the availability and scalability of the DCE infrastructure. This
means that each service actually consists of multiple servers running on
separate hosts. Should any single server become unavailable, clients can
quickly locate and use another server (replica) that provides the same
service.
The Security and Naming services replicate only their read operations.
That is, while a client can choose between any of the replicas to obtain
information, it must go to a specific replica — the master replica — to
perform a write operation. The master replica is then responsible for
informing the other (read-only) replicas of the change.
While the replication mechanisms of the Security Service and the
Naming Service differ in design and implementation, they share this
master-slave approach. Therefore, while both services can be considered