HP Serviceguard Extension for RAC (SGeRAC) manual Introduction to Serviceguard Extension for RAC

1 Introduction to Serviceguard Extension for RAC

Serviceguard Extension for RAC (SGeRAC) enables the Oracle Real Application Cluster (RAC), formerly known as Oracle Parallel Server RDBMS, to run on HP high availability clusters under the HP-UX operating system. This chapter introduces Serviceguard Extension for RAC and shows where to find different kinds of information in this book. The following topics are presented:

•“What is a Serviceguard Extension for RAC Cluster? ” (page 12)

•“Serviceguard Extension for RAC Architecture” (page 14)

•“Overview of SGeRAC and Cluster File System (CFS)/Cluster Volume Manager (CVM)” (page 14)

•“Overview of SGeRAC and Oracle 10g, 11gR1, and 11gR2 RAC” (page 16)

•“Overview of SGeRAC Cluster Interconnect Subnet Monitoring ” (page 17)

•“Node Failure” (page 19)

•“Larger Clusters ” (page 20)

•“Extended Distance Cluster Using Serviceguard Extension for RAC” (page 22)

What is a Serviceguard Extension for RAC Cluster?

A high availability cluster is a grouping of HP servers having sufficient redundancy of software and hardware components that a single point of failure will not disrupt the availability of computer services. High availability clusters configured with Oracle Real Application Cluster software are known as RAC clusters. Figure 1 shows the basic configuration of a RAC cluster on HP-UX.

Figure 1 Overview of Oracle RAC Configuration on HP-UX

In the figure, two loosely coupled systems (each one known as a node) are running separate instances of Oracle software that read data from and write data to a shared set of disks. Clients connect to one node or the other via LAN.

With RAC on HP-UX, you can maintain a single database image that is accessed by the HP servers in parallel and gain added processing power without the need to administer separate databases.

12 Introduction to Serviceguard Extension for RAC