User-Defined AWT Resource Limits | Teradata Vantage - 17.00 - User-Defined AWT Resource Limits - Teradata Workload Management

Teradata Vantageā„¢ - Workload Management User Guide

prodname
Advanced SQL Engine
Teradata Workload Management
vrm_release
17.00
created_date
June 2020
category
Administration
User Guide
featnum
B035-1197-170K

You can define custom AWT resource limits for utilities, and TASM will either reject or delay utilities that exceed these limits. To create custom limits, in the Throttles view, use the Resource Limits tab.

You may want to create a custom AWT resource limit for utility jobs for these reasons:
  • You want to enforce a lower percentage of AWTs for utility jobs than the system default.
  • You want to create separate AWT resource limits for utility jobs from different users or applications.
When you create a custom AWT resource limit for an application or user, the system-level rule and the application-specific or user-specific resource limit are enforced separately. However, all applicable rules must be satisfied before a utility can run.
For example, the DBA defined the following AWT resource limits in Viewpoint Workload Designer:
  • Rule 1: A limit of 45 percent of AWTs for all DSA restore jobs in the system, with delay
  • Rule 2: A limit of 15 percent of AWTs for DSA restore jobs from user Lee, with delay
With these limits, the following scenarios can occur:
  • Scenario #1: Only DSA restore jobs from user Lee are running. These jobs together cannot use more than 15 percent of AWTs.
  • Scenario #2: User Lee is not running any DSA restore jobs. Other users are running DSA restore jobs and consuming the limit of 45 percent of AWTs. When user Lee submits a DSA restore job, TASM delays it because it would exceed the AWT limit of Rule 1 (45 percent of AWTs for all DSA restore jobs).

You can see all the AWT Resource Limit rules in the Resource Limits by State tab in the Throttles view.

The following illustrates custom AWT resource limits for different groups of users.


"Custom AWT resource limits for different groups of users."

Keep in mind the following AWT requirements for each utility protocol, so that you can select the appropriate limits for your environment.
Utility Protocol AWTs Required To Start
FastLoad 3
MultiLoad 2
FastExport No Spool 2
MLOADX MIN(2, number of target tables)
DSA Backup 2
DSA Restore 3*

* TASM initially assumes a DSA restore job needs 3 AWTs. Actual AWT usage, which can be up to 55 AWTs, will be dynamically updated later in the job and will affect the next utility job.