SEQUENCER TAKEOVER - Teradata Unity

Purpose

Promotes the Standby Sequencer to the Active state if Unity is inactive and configured for manual failover.

Parameters

BY FORCE

This option forces a Standby Sequencer to become active if sequencers were in Not in Peer when the Active Sequencer went down, or if the repositories were not fully synchronized.

Recovery might not be possible when using the BY FORCE option. Because the Sequencer was not synchronized (Not in Peer) when it went down, the Sequencer that was forced to Active state might not have received all recovery log records.

Usage Considerations

This command is only valid if the Sequencers are in Peer state when the Active Sequencer went down. In this case, the Standby mode is Standby - Synchronized when the SEQUENCER TAKEOVER command is issued.

Examples

unityadmin>  SEQUENCER STATUS; 
unityadmin> 
HA Status            : Down/Unknown
Log Replication Mode : Asynchronous
Failover Mode        : Manual

Individual Sequencer States
---------------------------
        unknown host/port               : DOWN
        unity2:5344                     : STANDBY (SYNCHRONIZED)


Sequencer State Counts
----------------------

        Standby (Synchronized) Count    : 1
        Down Count                      : 1

---------------------------------------------
Process Identifier   : rb_seq
Process Type         : Sequencer
Region Name          : rb
Current Status       : Down
---------------------------------------------
Process Identifier   : to_seq
Process Type         : Sequencer
Region Name          : to
Current Status       : Up - Processing this Unityadmin connection
---------------------------------------------
Process Identifier   : to_wdg
Process Type         : Watchdog
Region Name          : to
Current Status       : Up
---------------------------------------------
Process Identifier   : rb_wdg
Process Type         : Watchdog
Region Name          : rb
Current Status       : Up

Run SEQUENCER TAKEOVER. Live operation updates display when running unityadmin in synchronous mode.

unityadmin>  SEQUENCER TAKEOVER; 
Operation Number : 1
Operation Name   : Sequencer Takeover
User             : admin
User Name        : Main Administration User
Start Time       : 01/17 15:44:17
Updates:
    01/17 15:44:17 [-] Info: Sending takeover request
    01/17 15:44:19 [-] Info: Sequencer HA takeover request succeeded
    01/17 15:44:19 [-] Info: Operation finished
Status      : Finished (1)
Finish Time : 01/17 15:44:19

If not running unityadmin in synchronous mode, unityadmin provides an operation number.

unityadmin>  SEQUENCER TAKEOVER; 
The request is currently processing as operation number 1.
You may check its status using the command 'operation check 1'.

If not running in synch mode, you can run OPERATION CHECK with the provided operation number to view details.

unityadmin>  OPERATION CHECK 1; 
Operation Number : 1
Operation Name   : Sequencer Takeover
User             : admin
User Name        : Main Administration User
Progress (%)     : 100
Status           : Finished (1)
Start Time       : 01/17 15:45:46
Finish Time      : 01/17 15:45:47
Updates:
    01/17 15:45:46 [-] Info: Sending takeover request
    01/17 15:45:47 [-] Info: Sequencer HA takeover request succeeded
    01/17 15:45:47 [-] Info: Operation finished

Once the operation completes, you can run SEQUENCER STATUS to verify that the Standby Sequencer is in Active state.

unityadmin>  SEQUENCER STATUS; 
HA Status            : Not In Peer (Cannot failover)
Log Replication Mode : Asynchronous
Failover Mode        : Manual

Individual Sequencer States
---------------------------
        unknown host/port               : DOWN
        unity2:5344                     : ACTIVE


Sequencer State Counts
----------------------

        Active Count                    : 1
        Down Count                      : 1

---------------------------------------------
Process Identifier   : rb_seq
Process Type         : Sequencer
Region Name          : rb
Current Status       : Down
---------------------------------------------
Process Identifier   : to_seq
Process Type         : Sequencer
Region Name          : to
Current Status       : Up - Processing this Unityadmin connection
---------------------------------------------
Process Identifier   : to_wdg
Process Type         : Watchdog
Region Name          : to
Current Status       : Up
---------------------------------------------
Process Identifier   : rb_wdg
Process Type         : Watchdog
Region Name          : rb
Current Status       : Up