A standby HiRDB is provided in addition to the HiRDB that performs the business processing, and the business processing is switched automatically to the standby HiRDB if an error occurs in the HiRDB performing the business processing. This is called the standby system switchover facility.

The standby system switchover facility is implemented in a cluster system configuration that uses multiple server machines. In a HiRDB single server configuration, systems are switched over in system units. Note, however, that a utility special unit cannot perform system switchovers. In a HiRDB parallel server configuration, systems are switched over in units. If you use user server hot standby or the rapid system switchover facility, you can shorten the time required to perform a system switchover. For details about user server hot standby and the rapid system switchover facility, see 26.7.7 Reducing the system switchover time (user server hot standby, rapid system switchover facility).

The system performing the business processing is called the running system, and the system that is standing by is called the standby system. Each time a system switchover is performed, the running system becomes the standby system and the standby system becomes the running system. Further, to differentiate between the two systems during system construction and environment setup, the first system to start as the running system is called the primary system, and the system that starts initially as the standby system is called the secondary system. Although the running system and the standby system change designations when a system switchover occurs, the primary system and secondary system do not ever change those designations. The following figure provides an overview of the system switchover facility (standby system switchover facility).

Figure 26-2 Overview of the system switchover facility (standby system switchover facility)

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For details about shared disk units, see the following subsections.

For standby system switchovers (monitor mode): 26.2.4(2) Preparing a shared disk unit

For standby system switchovers (server mode): 26.3.4(2) Preparing a shared disk unit

For standby-less system switchovers (1:1): 26.4.3(2) Preparing a shared disk unit

For standby-less system switchovers (effects distributed): 26.5.2(2) Preparing a shared disk unit

Explanation

If an error occurs on the running system, the standby system is notified of the error, the systems are switched, and the standby system takes over the business processing as the running system.

Notes about using ClusterPerfect

This manual refers to the running system of ClusterPerfect as the primary system, and the secondary system of ClusterPerfect as the standby system.