Self-Healing Unrecoverable Tables | Teradata Unity - 17.00 - Self-Healing Unrecoverable Tables - Continuous Availability - Teradata Unity

Teradata® Unity™ User Guide

Product
Continuous Availability
Teradata Unity
Release Number
17.00
Published
September 2020
Language
English (United States)
Last Update
2020-09-15
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Unity self-healing feature can automatically validate, re-synchronize, and re-activate unrecoverable tables. Tables may become unrecoverable when a session encounters data inconsistency with multiple tables involved in the request. Only one of the involved tables may be out of sync. The rest of the tables can be automatically re-synchronized after they are validated.

If the self-healing feature is enabled, Unity runs it automatically, with default intervals of 10 minutes, to re-activate unrecoverable tables found to be in-sync. The Unity table synchronization service automatically re-synchronizes other out-of-sync tables.

Enable this feature with the following unityadmin command:
config update AutoSelfHealingInterval 600 reason 'Enable Self-healing';
config update AutoTableValidateAttempts 1 reason ‘Enable Self-healing’;
You can optionally set this self-healing feature to validate only tables or to validate and then synchronize tables using the configuration setting AutoSelfHealingOptions.
  • If set to 0, self-healing validates and activates the out-of-sync table.
  • If set to 1, self-healing validates, synchronizes, and then activates the out-of-sync table.
config update AutoSelfHealingOptions 1 reason 'Enable Self-healing table sync';
You can specify replication options for individual tables. If not specified on an individual table, the DefaultObjectResyncOption is used to determine whether the table is synchronized.
config update DefaultObjectResyncOption 2 reason ‘Enable Self-healing table sync’;
You can also specify a timeout for each table for the replication option. If not specified, the default value set by the configuration setting is used.
config update DefaultObjectResyncTimeout 600 reason 'Setting global resync timeout';