(a) Processing difference depending on the operand specification

When notwait is specified in the pd_ha_mgr_rerun operand, HiRDB does not wait to receive a startup processing completion notification from each unit during a system switchover for the system manager unit (at the time of startup processing at the switching destination). The following table describes how HiRDB processing differs depending on the value specified in the pd_ha_mgr_rerun operand.

Table 26-41 Processing by HiRDB depending on the value specified in the pd_ha_mgr_rerun operand

Item	pd_ha_mgr_rerun value
	wait (default value)	notwait
Whether a system switchover for the system manager unit can occur when there is a stopped unit.	The system switchover cannot be executed (system switchover fails).	The system switchover can be executed.#1, #2

#1

When notwait is specified in the pd_ha_mgr_rerun operand, HiRDB does not perform version checking of the units or the system configuration check. Therefore, the time required to perform a system switchover of the system manager unit is reduced.

#2

When a system switchover for the system manager unit is complete, the KFPS05210-I message (system startup completion message) is output, even if the HiRDB operating environment is not complete (for example, no front-end server is active).

(b) Required system configuration

When notwait is specified in the pd_ha_mgr_rerun operand, the system must be configured so that all the conditions listed below are satisfied. If you cannot satisfy the conditions, see (2) Using reduced activation.

• The rapid system switchover facility is used for the system manager unit.
• Only the rapid system switchover facility is used for units subject to system switchovers (the user server hot standby function or a standby-less system switchover facility cannot also be used).
• The system manager and the dictionary server are defined in the same unit.
• A HiRDB parallel server configuration consists of at least two units.
• HiRDB Datareplicator is not being used.

(c) Specifying the environment settings

Use the following procedure to specify the environment settings.

Procedure

1. Use the pdadmvr command to check that all units in the primary and standby systems are of the same version.
2. Specify notwait in the pd_ha_mgr_rerun operand.
   

   Reference note

   When notwait is specified in the pd_ha_mgr_rerun operand, HiRDB does not perform unit version checking when a system switchover for the system manager unit occurs. Because correct HiRDB operation cannot be guaranteed if there is a version mismatch between units, you must perform step 1 to make sure that all units are of the same version.

(d) Notes about system switchovers for the system manager unit

When jobs cannot be executed after a system switchover for the system manager unit

When a system switchover for the system manager unit is complete, the KFPS05210-I message (system startup completion message) is output, even if the HiRDB operating environment is not complete (for example, no front-end server is active). Consequently, if jobs cannot be executed after completion of a system switchover for the system manager unit, a UAP could terminate in an error. For this reason, use the pdls command to check the operating status of each server.

When a system switchover for the system manager unit occurs while HiRDB is starting or terminating

If a system switchover for the system manager unit occurs while HiRDB is starting (or terminating), the system manager unit starts (or terminates) regardless of the operating status of other units. Therefore, units other than the system manager unit might not be able to start (or terminate). If this happens, you must forcibly terminate HiRDB.

You can avoid this situation by taking the following actions when you start or terminate HiRDB:

• When starting HiRDB
  Make sure HiRDB has started completely, and then start the system manager unit of the standby system.
  
• When stopping the HiRDB system
  First terminate the system manager unit of the standby system, and then terminate HiRDB.
  

About the status of the stopped unit

After a system switchover, you can execute the pdls -d svr command for a unit that was stopped at the time of the system switchover for the system manager unit. STOP(N), indicating normal termination status following execution of the pdstop command, will be displayed as long as the unit remains stopped.

If a network error causes the unit to remain in STOP(N) status, even though it has actually started, first resolve the network error, terminate the unit, and then restart it.

When there is a stopped unit in the system, system switchovers for the system manager unit can be performed if the following operands are specified:

• pd_start_level = 1
• pd_start_skip_unit = unit-identifier-of-stopped-unit
• pd_reduced_check_time = wait-time-until-notification-of-reduced-activation-startup

The following table describes how to specify these operands, and it shows the actions HiRDB takes during a system switchover.

Table 26-42 Operands related to reduced activation and actions HiRDB takes during a system switchover

Condition		Actions HiRDB takes when a system switchover occurs for the system manager unit
pd_start_level specification value	pd_start_skip_unit specification
0 (default value)	--	If there is a stopped unit, a system switchover for the system manager unit fails.
1	Not specified	Even if there is a stopped unit, a system switchover for the system manager unit executes. However, a wait occurs for receipt of a startup processing completion notification from each unit. This notification wait time is specified in the pd_reduced_check_time operand (the default value is 20 minutes).
	Specified	If the stopped unit is specified in the pd_start_skip_unit operand, a system switchover for the system manager unit executes. No notification wait time occurs.

Legend:

--: Need not be specified.

Reference note

• If a system switchover occurs while there are units that are stopped, the operating status of such units cannot be determined. As a result, the system switchover might fail or might take a long time to finish.
• Even if 1 is specified in the pd_start_level operand, if any of the following conditions is not satisfied, a system switchover for the system manager unit fails:
  A front-end server is active
  A back-end server is active
  A dictionary server is active
  
• When a system switchover for the system manager unit occurs, the unit specified in the pd_start_skip_unit operand is not recognized, regardless of whether the unit specified in this operand has started. If a stopped unit inside the system becomes enabled for starting after you have specified the pd_start_skip_unit operand, delete the specification of this operand.
• To use the reduced mode facility, see 20.15 Handling of reduced activation (HiRDB parallel server configurations only).

When you specify the pd_start_skip_unit operand, you must terminate HiRDB. Therefore, consider (1) Specifying the pd_ha_mgr_rerun operand if your system must remain active around the clock.