Compaq AA-Q88CE-TE manual Partition Management Managing Partitions, Controlling the Active Site

Partition Management

3.6 Managing Partitions

If a partition enters a wait state or fails but has neither a local or remote journal, an operator can instruct RTR to skip the current step in the recovery process with the /IGNORE_RECOVERY qualifier. Since this command bypasses parts of the recovery cycle use it with caution in cases where availability above consistency in application databases is desired.

The recovery cycle can also be manually restarted with the /RESTART_RECOVERY qualifier. This may be useful if the operator previously aborted automated recovery. Since this command can result in recovery of transactions from previously inaccessible journals, do not use this if your applications are sensitive to the order in which transactions are processed by the servers.

3.6.3.1Command Line Example

Example of the qualifiers:

RTR> SET PARTITION/FACILITY=Facility1/IGNORE_RECOVERY Facility1:Partition1

RTR>

RTR> SET PARTITION/FACILITY=Facility1/RESTART_RECOVERY Facility1:Partition1

A complete description of the qualifiers to the SET PARTITION command can be found in Chapter 6.

3.6.3.2 Programming Information

To terminate the current recovery state, program the set_qualifier argument of rtr_set_info( ) as follows:

rtr_qualifier_value_t	set_qualifiers[ 2 ];
rtr_partition_state_t	newState = rtr_partition_state_exitwait;

set_qualifiers[ 0 ].qv_qualifier = rtr_partition_state; set_qualifiers[ 0 ].qv_value = &newState; set_qualifiers[ 1 ].qv_qualifier = rtr_qualifiers_end; set_qualifiers[ 1 ].qv_value = NULL;

To restart recovery, specify newState as rtr_partition_state_recover.

3.6.4 Controlling the Active Site

RTR lets the system operator to deploy a range of shadow and standby partitions in order to provide the desired degree of application resilience to failures. By default, RTR automatically manages the assignment of active and standby roles to the available partition instances. The operator can assign a relative priority to each backend on which a partition instance exists. Enter priority as a list of backend node names with the highest priority first in decreasing order. See the command example Section 3.6.4.1.

Suspend transaction presentation before entering or changing the priority list.

3.6.4.1 Command Line Example

RTR> SET PARTITION/PRIORITY_LIST=(BE1, BE2, BE3) Facility1:Partition1

For more information on the SET PARTITION command see Chapter 6.

Partition Management 3–7