Compaq AA-Q88CE-TE User Manual

Page 47

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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.

3.6.3.1 Command 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

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