Compaq AA-Q88CE-TE manual Controlling Failover, Char

Partition Management

3.6 Managing Partitions

3.6.4.2 Programming Information

To set the partition backend priority list, program the set_qualifier argument of the rtr_set_info( ) call as follows:

rtr_qualifier_value_t		set_qualifiers[ 2 ];
char	*szNodeList =	"your,list,of,node,names,here"

set_qualifiers[ 0 ].qv_qualifier = rtr_partition_be_priority_list; set_qualifiers[ 0 ].qv_value = &szNodeList;

set_qualifiers[ 1 ].qv_qualifier = rtr_qualifiers_end; set_qualifiers[ 1 ].qv_value = NULL;

3.6.5 Controlling Failover

In a system configured for maximum fault tolerance employing both shadows and standbys, there is a choice to be made in case of the failure of the primary site. The qualifier to the SET PARTITION command of /FAILOVER_POLICY= allows the system operator to select one of the following policies that RTR should pursue in selecting the new primary site in the event of a failure:

•/FAILOVER_POLICY=STANDBY causes RTR to choose a standby of the failed primary (if any) to become the new primary. If there is more than one standby, the operator may addition use the priority list feature (described above) to control which standby is preferred. Depending on the size of the journal of the failed primary, there will be a hold up in the processing of transactions whilst the journal is recovered. This is the default behaviour.

•/FAILOVER_POLICY=SHADOW instructs RTR to make the active secondary (if any) the new primary. A standby of the failed primary (if any) will be elected to become the new secondary. This option gives the shortest fail over time, but will move the primary to a different cluster that you may have located at a different site.

•/FAILOVER_POLICY=COMPATIBLE_PRE_V32 is a mode that will operate with configurations that contain RTR routers running versions of the software prior to V3.2. This mode will be automatically adopted if such routers exists in or join the configuration.

3.6.5.1Command Line Example

An example use of the /FAILOVER_POLICY qualifier:

RTR> SET PARTITION/FAILOVER_POLICY=SHADOW Facility1:Partition1

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

3.6.5.2 Programming Information

To set the partition failover policy, program the set_qualifier argument of the rtr_set_info( ) call as follows:

rtr_qualifier_value_t set_qualifiers[ 2 ]; rtr_partition_failover_policy_t newPolicy;

set_qualifiers[ 0 ].qv_qualifier = rtr_partition_failover_policy; set_qualifiers[ 0 ].qv_value = &newPolicy;

set_qualifiers[ 1 ].qv_qualifier = rtr_qualifiers_end; set_qualifiers[ 1 ].qv_value = NULL;

Legal values for newPolicy are:

•rtr_partition_fail_to_standby

3–8Partition Management