17.00 - Offline AMPs - Parallel Transporter

Teradata® Parallel Transporter Application Programming Interface Programmer Guide

prodname
Parallel Transporter
vrm_release
17.00
created_date
June 2020
category
Programming Reference
featnum
B035-2516-220K

The impact of offline AMPs on the Update driver depends on:

  • The number of offline AMPs in a cluster, either logically or physically
  • The operational phase of the Update tasks when the offline AMP condition occurs
  • Whether the target tables are fallback or nonfallback

The table below describes the impact of offline AMPs on Update driver tasks on fallback and nonfallback tables.

Offline AMP Conditions and Effects on Update Driver Tasks 
If... And... Then...
All of the target tables are fallback Not more than one AMP is offline Update driver tasks continue to run as long as there is not more than one AMP offline in a cluster, either logically or physically.

The offline AMP does not participate in the application phase if:

  • The AMP goes offline before the Update tasks enter the application phase, and the AmpCheck attribute is set to None.
  • Certain I/O errors occur during the application phase.
Two or more AMPs are offline Update driver tasks do not run or terminate if two or more AMPs are offline in a cluster, either logically or physically.
In the application phase, if AMPs are offline to the extent that data on the disk is corrupted, then you must restore the affected tables.
One or more of the target tables is nonfallback One or more AMPs are offline Update driver tasks terminate and you cannot restart until all of the AMPs are online.
The Update driver also terminates if I/O errors corrupt the target tables in the application phase.