Determining Workloads for the SLG Tier - Teradata Database - Teradata Viewpoint

Workload Pre-Migration User Guide
Product
Teradata Database
Teradata Viewpoint
Published
January 2016
Language
English (United States)
Last Update
2018-05-07
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Product Category
Analytical Ecosystem
Software

In SLES 11, the highest scheduling priority is given to workloads in the Tactical tier, with the next highest priority being given to workloads in the SLG tiers.

SLG tiers are available only with TASM licensing.

The SLG tier is for workloads that are associated with a short service level goal or service level expectation; require a short response time due to business importance; and do not generally consume a significant amount of CPU resources. Although critical to the business, SLG workloads are secondary in importance to tactical workloads.

SLG Workload Criteria

When considering which workloads to associate with the SLG tier, expect fewer than ten, if any, to qualify. To make a determination, specifically consider the following criteria.
  • The service level goal or agreement assigned to the workload.
  • The importance to the business of the workload.
  • The relative weight value of the corresponding allocation group.
    You can use the Workload Mapping tab in the Teradata Viewpoint Workload Designer portlet to ascertain workload-to-allocation group relationship. To find information on allocation group relative weight and CPU resource consumption, use the ResUsageSPS table or pie charts in the Teradata Viewpoint Workload Monitor portlet.
    The Workload Monitor portlet shows the relative weight that an allocation group would be assigned if all defined allocation groups were active. Therefore, relative weights of some allocation groups may actually be smaller at run time than the portlet indicates. Conversely, the ResUsageSPS table reflects relative weights as calculated by Priority Scheduler at run time based only on the active allocation groups.
  • The amount of CPU resources consumed by the workload at peak processing times.
  • The typical run time, expected resource demands, and the business importance of the work destined for the workload.

SLG Workload Identification Process Overview

In general, only non-tactical but business-critical workloads associated with service level goals or agreements should be considered for the SLG tier. After identifying each such workload, complete the following steps to assess candidacy for SLG-tier assignment.
  1. If the service level goal or agreement is 10 seconds or longer, assign the workload to the Timeshare tier. Otherwise, proceed to the next step.
  2. If the CPU consumption at peak processing times is higher than the relative weight of the allocation group, assign the workload to the Timeshare tier. Otherwise, proceed to the next step.
  3. If the expected run time is long and the resource demands are great, assign the workload to the Timeshare tier. If, however, the expected run time is short and the resource demands are minimal, the workload may be a good candidate for the SLG tier.
The following flowchart illustrates this process.

SLG Workload Identification Process Modifications

The assessment process may yield no candidate workloads for the SLG tier. In this case, consider expanding the scope to include workloads with slightly longer service level goals or agreements, such as 20 or 30 seconds, or workloads with a slightly higher CPU-consumption value than allocation group relative weight.

Conversely, the process may indicate that a higher than recommended number of workloads qualify for SLG tier assignment. In this case, investigate whether the cause is business-critical, short-running work being spread across many workloads. If so, and the total CPU-consumption value of the workloads is low to moderate (for example, no more than 25% combined), consider expanding the total number of workloads assigned to the SLG tier beyond the recommended single-digit scope.