Programming Group Services for RSCT

This information is intended for programmers of applications that manage system resources, which may or may not be subsystems, who want to use Group Services to make their applications highly available. This publication contains information for programmers who want to write new clients that use the Group Services application programming interface (GSAPI) or who want to add the use of Group Services to existing programs.

It assumes that you are an experienced C programmer and have a thorough understanding of the fundamentals of the AIX, Linux, Solaris, or Windows operating system, depending on your system environment.

To use the subroutines described in this publication, you need appropriate privileges and authorizations. To use the GSAPI subroutines, the calling process needs to have an effective group ID (EGID) of hagsuser, an effective user ID (EUID) of root, or an EUID that is a member of the hagsuser group.

Group Services help in the design and implementation of fault-tolerant applications, and in the consistent recovery of multiple applications. They also accomplish these two distinct tasks in an integrated framework. They offer a simple programming model because it is based on a small number of core concepts: it is a cluster-wide group membership and synchronization service based on the publish/subscribe model, which maintains an application-specific state for each group.

For information about managing the Group Services subsystem and its daemons, see the Administering RSCT guide.