Nonstop Database, HiRDB Version 9 System Operation Guide

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26.9.4 Operating procedures after a system switchover

IP addresses are not inherited when the standby-less system switchover (effects distributed) facility is used. When IP addresses are not inherited, the host names are different for the primary system and the secondary system, so you need to perform the operations described below.

Additionally, because the switching destination differs for each server, the host name of the switching destination is used after a system switchover.

Organization of this subsection
(1) Operation commands and utilities
(2) Messages
(3) Acquisition of statistical information

(1) Operation commands and utilities

If a system switchover occurs while a server is active, each server defined in the unit where the error occurred must be operated as a server belonging to the accepting unit. Because the switching destination differs for each server, servers cannot be operated in a group as a regular unit after a system switchover occurs.

For this reason, you must specify the values listed in the following table when you issue operation commands.

Table 26-75 Specification values for operation commands when the standby-less system switchover (effects distributed) facility is used

Type of command Specification value
Before switching After switching
Host name specification command Host name of the regular unit Host name of the accepting unit
Unit identifier specification command Unit identifier of the regular unit Unit identifier of the accepting unit
Server name specification command Operation target server name Operation target server name

In operations in which a host name or unit identifier is specified, the processing target differs before and after a system switchover. Therefore, when the standby-less system switchover (effects distributed) facility is used, it is advisable to use operations that provide for server name specification.

When a host name is displayed in the processing results of an operation command, it is the host name of the accepting unit that is displayed.

The table below lists, for the standby-less system switchover (effects distributed) facility, the execution targets when operation command options are specified. Be aware that the execution targets of the pdstart and pdstop commands are different from those listed in the table. For details about the pdstart and pdstop commands, see 26.9.1 Differences in the HiRDB operating procedures.

Table 26-76 Execution targets when operation command options are specified (for the standby-less system switchover (effects distributed) facility)

Option Condition Command's execution target
-u -s Unit where system manager is defined Target server
No No -- -- System (or all running back-end servers in the system)
Yes Offline -- Specified server that is a back-end server of the primary system in the regular unit
Online Offline Specified server that is a back-end server of the primary system in the regular unit
Online Specified server that is a running back-end server of the running system unit
Yes No -- -- Specified unit (or all running back-end servers in the specified unit)
Host Offline -- Specified unit that is a host BES in the specified regular unit
Online Offline Specified unit that is a host BES in the specified regular unit
Online Specified server that is a running BES in the running system unit (-u specification is ignored)
Guest Offline -- Specified server that is a guest BES in the specified accepting unit
Online Offline Specified server that is a guest BES in the specified accepting unit
Online Specified server that is a running back-end server in the running system unit (-u specification is ignored)

Legend:
--: Not applicable

(2) Messages

The host name of the accepting unit is displayed in messages.

(3) Acquisition of statistical information

For details about how statistical information is collected after a system switchover, see 26.9.1(4)(b) Process for collecting statistical information after a system switchover.