dbcc options for high availability systems

Table C-4 includes information about the dbcc ha_admin options.

**Table C-4: dbcc ha_admin options**
Option name	Function	Syntax and comments
rollback_failback	Rolls back the effect of sp_companion... prepare_failback and returns the companion to failover mode. This command works regardless of the results of the prepare_failback command.	dbcc ha_admin (" ", rollback_failback) Where `“ “` is a required empty placeholder. Can be used only in failback mode. Any failback threads waiting for the resume command are killed when this command is executed. You may need to perform platform-specific steps to prepare your companions for the rollback_failback option. See the appropriate chapter in this manual for more information. You can issue this command only from the secondary companion.
rollback_failover	Rolls back the effects of fail over from the primary companion, and returns it to normal companion mode. rollback_failover does not affect the secondary companion.	dbcc ha_admin (" ", rollback_failover) Where `“ “` is a required empty placeholder. This command can be used only in failover mode. You may need to perform platform-specific steps to prepare you companions for the rollback_failover option. See the appropriate chapter in this manual for more information. rollback_failover has no effect on the companion server that failed. The companion server that takes over the failed companion’s workload resumes normal companion mode. You can issue this command only from the secondary companion. This command works even when fail over has marked the databases “suspect.”
drop_failoverdb	Used only in failover mode. drop_failoeverdb drops the failed-over databases that could not be dropped with the drop database command. This command also cleans up the master_companion of all the metadata relating to the dropped database.	dbcc ha_admin (" ", drop_failedoverdb, database_name) Where `" "` is a required empty placeholder, and database_name is the name of the database you are dropping. Use only as a last resort, when you must drop a database to complete the load of another database.
clusterlock	Acquires or releases cluster-wide locks during a cluster operation.	dbcc ha_admin (" ", clusterlock, [acquire \| release]) For more information about cluster-wide locks and releasing them, see “Cluster locks in a high availability node”.
state_machine	Moves the companion server to single-server mode.	dbcc ha_admin (' ', 'state_machine', 'halt') Where `" "` is a required empty placeholder. For information about using this option, see Appendix A.
session	Invokes clients that are sleeping because of a failed sp_companion...resume. Clients that are invoked disconnect from the secondary companion and connect to the primary companion.	dbcc ha_admin (SYB_HACMP, session, "drop")