What is an OPS Cluster?

MC/LockManager enables the Oracle Parallel Server RDBMS to run on HP 9000 high availability clusters under the HP-UX operating system.

A high availablity cluster is a grouping of HP 9000 series 800 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 Parallel Server are known as OPS clusters. Figure 1-1 “Overview of Oracle Parallel Server Configuration on HP-UX ” shows a very simple picture of the basic configuration of an OPS cluster on HP-UX.

Figure 1-1 Overview of Oracle Parallel Server Configuration on HP-UX

In the figure, two loosely coupled HP 9000 series 800 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.

OPS on HP-UX lets you maintain a single database image that is accessed by the HP 9000 servers in parallel, thereby gaining added processing power without the need to administer separate databases. MC/LockManager handles issues of concurrent access to the same resources by different servers and ensures data integrity. Further, when redundant LAN hardware and disk mirroring are used, MC/LockManager provides a highly available database that continues to operate even if one hardware component should fail.

Using Packages in an OPS Cluster

In order to make other important applications highly available (in addition to the Oracle Parallel Server RDBMS), you can configure your OPS cluster to use packages. Packages group applications and services together; in the event of a service, node, or network failure, MC/LockManager can automatically transfer control of all system resources in a designated package to another node within the cluster, allowing your applications to remain available with minimal interruption.

	NOTE: In OPS 8.0.5, you create packages to start and stop OPS itself as well as to run applications that access the database instances. In OPS 7.3.x, however, you use special DLM runhalt scripts instead of packages to start and stop the OPS instances. For details on the use of packages with OPS, refer to the chapter "Configuring Packages and Their Services."