If you use the system switchover facility, make sure that with the HiRDB servers for the source Datareplicator you use grouped-system switchover (system switchover mode in which multiple products are grouped so that the entire group is subject to system switchover). For the target Datareplicator, use grouped-system switchover as needed.

This subsection describes the system switchover types supported by HiRDB. For details about each type of system switchover, see the related cluster software manual.

Automatic system switchover

When an error occurs in the running system, system switchover occurs automatically.

Planned system switchover

System switchover is implemented intentionally by the user by executing a cluster software command at the running system.

Grouped-system switchover can be implemented in either of the above two modes.

Other functions for reducing the HiRDB system switchover time include high-speed system switchover, user server hot standby, and transaction queuing.

The system switchover facility supports the following system configurations:

1-to-1 switchover organization

There is a one-to-one correspondence between a running system and a standby system.

2-to-1 switchover organization

There is a two-to-one correspondence between running systems and a standby system.

Mutual system switchover configuration

The same server machine contains both the running system and the standby system.

The mutual system switchover configuration requires a definition in order to use predefined error information files.

The following table lists the subsections that provide the details of different system switchover configurations.

Table 6-17 Subsections providing the details of different system switchover configurations

Cluster software used	System switchover configuration	Subsection
HA monitor	1-to-1 switchover configuration 2-to-1 switchover configuration	6.9.2 Preparations for using the system switchover facility (for HA monitor) 6.9.4 Handling procedure when the system switchover facility is used (for HA monitor)
	Mutual system switchover configuration	6.9.2 Preparations for using the system switchover facility (for HA monitor) 6.9.4 Handling procedure when the system switchover facility is used (for HA monitor) 6.9.5 Notes on using the system switchover facility
	Standby-less system switchover (effects distributed) facility	6.9.4 Handling procedure when the system switchover facility is used (for HA monitor) 6.9.6 Using the standby-less system switchover (effects distributed) facility
Microsoft Cluster Server	1-to-1 switchover configuration	6.9.3 Preparations for using the system switchover facility (for Microsoft Cluster Server)