Supported State Transitions | Teradata Business Continuity Manager - Supported State Transitions - Teradata Business Continuity Manager

Teradata® Business Continuity Manager User Guide

Product
Teradata Business Continuity Manager
Release Number
1.0
Published
January 2022
Language
English (United States)
Last Update
2022-01-27
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B035-2550
lifecycle
previous
Product Category
Analytical Ecosystem
This following table describes Business Continuity Manager system and table states and supported transition states.
Current State Description Supported State Transitions
Active: Table is available for read and write operations. There is only one active system.
  • OOS: Halts access to a table or system to perform maintenance operation.
  • Read-Only: Freezes the table. A table may also automatically be placed in read-only if a session encounters an error and the SetReadOnlyOnWriteFailure parameter is set to True.
Standby: Database table is up-to-date and available for failover read and write operations. Active
Interrupted: An error occurred on the standby system for a query that succeeded on the active system. This error is potentially recoverable. Until the system recovers from the interruption, tables in this state are unavailable. For example, when a session cannot be opened on a Teradata Database system due to insufficient system resources, the state changes to Interrupted. Restore: Table recovers automatically. Investigate the problem that caused the interruption before attempting to restore to an Active state. If the problem is not resolved, the interruption may reoccur.

After the problem is resolved, to force recovery, place the table in the Restore state. This synchronizes data and sets the table state to the Active state.

Read-Only: Only read access is allowed to the Teradata Database system or table. Read requests are sent to the standby system in the event of a failover. Restore: Use this state to change the table to Read/Write. This state synchronizes data and sets the table state to the Active or Standby state as appropriate.
Restore: Table is in active recovery operation. Business Continuity Manager applies any missed write operations from Recovery Log. Active: After restore completes, verify the table was successfully recovered and placed in the Active or Standby state as appropriate.
OOS: No read or write requests are sent to this table in the Out of Service state. Restore: To recover from this state, place the table in the Restore state. This synchronizes data and sets the table state to the Active or Standby state as appropriate.
Unrecoverable: System or table is unavailable. Business Continuity Manager does not automatically recover a table in the Unrecoverable state because Business Continuity Manager does not recognize the state of the data. Active
  • For database tables: Tables in the Unrecoverable state must be synchronized manually. You cannot restore a table if it is unrecoverable on one system and active on another. You must mark the active table as unrecoverable and activate the table across all systems.
  • For Teradata systems: During configuration, a Teradata system is first placed in an Unrecoverable state. If all systems are Unrecoverable, you must manually synchronize the data across all your Teradata systems. You can activate all systems in the Components pane.