17.10 - Available AWTs - Advanced SQL Engine - Teradata Workload Management

Teradata Vantageā„¢ - Workload Management User Guide

Product
Advanced SQL Engine
Teradata Workload Management
Release Number
17.10
Release Date
July 2021
Content Type
Administration
User Guide
Publication ID
B035-1197-171K
Language
English (United States)

AMP Worker Tasks (AWTs) are the tasks inside each AMP that do database work. This work may relate to user requests or internal software functions, such as deadlock detection, error logging, or aborts.

Each AMP is given a number of AWTs at startup. If all AWTs are busy when new work arrives, the work waits in a queue until an AWT is free.

You can create a system event based on Available AWTs. To create the event, you specify the # of AMPs that have the number of Available AWTs you specify. For example, you can specify that the Available AWTs system event triggers if 2 AMPs each have only 1 available AWT. There are two ways to interpret Available AWTs: AWTs reserved only for new work or the entire unreserved pool. You can define Available AWTs appropriately for your site in the Other tab of the General view. In most systems, there is a limit of 50 AWTs that are available to support new work.

Note that if this event has a qualification time, the threshold does not have to be maintained on the same AMP over the entire qualification period. This means that if you define a threshold of 2, and AMP A crosses this threshold on one event sample and AMP B crosses the threshold on the next event sample, the event condition is considered to be maintained across the two samples.

For more details on AWTs and flow control, see the Orange Book, Teradata AMP Worker Tasks and ResUsage Monitoring, 541-0009643.