16.10 - Manually Intervening During a Split Brain Scenario - Teradata Unity

Teradata Unity User Guide

Product
Teradata Unity
Release Number
16.10
Published
January 2018
Language
English (United States)
Last Update
2018-03-29
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If a Split Brain Scenario cannot be automatically resolved by Unity, the Sequencers and their respective repositories will be disabled. This shuts down the operation of Unity. You must correct the Split Brain manually. Follow these steps to enable the Sequencers:
  1. Identify the SQL statements that were executed during the Split Brain event and the objects affected by the SQL statements.
  2. Verify the objects are synchronized. Synchronization means the object definition and content are consistent across all managed database systems. If these objects are not synchronized, manually synchronize these objects.
  3. Stop the disabled Sequencers.
  4. Choose the Sequencer to become active.
  5. Choose the Sequencer to become standby.
  6. Access a Unity server to sync the repositories.
    1. Go to the directory: /opt/teradata/unity/repository
    2. Locate the script: repositorySync.sh
    3. Execute the script with the command repositorySync.sh -fixStates.
    4. Follow the prompts using the Active Sequencers' repository as the source repository and the Standby Sequencer's repository as the destination repository.
  7. Delete the Recovery Log on the Standby Sequencer. The default location of the Recovery Log is /recovery/recovery.log
  8. Start the Unity processes.