Understanding the Workload Migration Process - 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
Because of the different approaches taken to priority scheduling in SLES 10 and SLES 11, the database that houses workloads must undergo conversion as part of the operating system upgrade. Although some aspects of the required conversion occur automatically when the applicable script is run during the upgrade process, a certain degree of manual intervention is required to emulate SLES 10 workload-scheduling behavior in SLES 11. If your upgrade scenario allows, use the Pre-Migration Tool to facilitate this process before transitioning to SLES 11.
Using the Pre-Migration Tool increases the likelihood of emulating existing priority-scheduling behavior upon operating system upgrade. The tool cannot be used after upgrade.

Preparing Workloads for Migration

Use the Pre-Migration Tool to:
  • Control which rule sets and, therefore, workloads to migrate. When you select rule sets for migration, only those rule sets and their corresponding workloads are migrated.
    The ability to control which rule sets are migrated applies only to the following versions of Teradata Database: 13.10; 14.0 lower than 14.0.4.1; and 14.10 lower than 14.10.1.1. Otherwise, all SLES 10 rule sets and workloads are migrated, regardless of whether the tool is used.
  • Distribute workloads among tiers.
  • Change allocation percentages for SLG workloads.
    SLG tiers are available only with Teradata Active System Management (TASM) licensing. Teradata Integrated Workload Management (IWM) licensing provides the Tactical and Timeshare tiers only.
  • Adjust access levels for timeshare workloads.

The Pre-Migration Tool writes output directives into a pre-migration table called tdwm.premigrate. When the TDWMDIP program is run after upgrading the operating system, the SLES 10 Teradata Workload Manager (TDWM) rule sets, including corresponding workloads, are migrated to SLES 11 based on the directives within the tdwm.premigrate table.

Migration without Workload Preparation

If you do not use the Pre-Migration Tool or do not implement any changes when using the tool, the tdwm.premigrate table remains empty of directives, and workload migration defaults to an automated process. In such cases, a higher degree of post-upgrade configuration may be required to emulate existing priority-scheduling behavior, as compared to the post-upgrade configuration necessary when using the Pre-Migration Tool.
In the absence of workloads, as is the case with SLES 10 appliance-licensed systems, you cannot use the Pre-Migration Tool when upgrading to SLES 11. In such scenarios, performance groups are migrated in a default manner. Use the Workload Designer portlet in Teradata Viewpoint to review and adjust as necessary workload-management settings to meet priority-scheduling goals.

Other Workload Migration Considerations

The migration process yields a pre-configured exception for tactical workloads, regardless of whether the Pre-Migration Tool is used. The process also sets pre-configured system-wide limit and reserve values for the Always planned environment. You cannot change the exception or the limit and reserve values before workload migration. However, with IWM licensing, you can subsequently use the Workload Designer Portlet in Teradata Viewpoint to change the reserve values or exception; TASM licensing provides for changing values for these parameters as well as limit values.

Regardless of whether you use the Pre-Migration Tool to prepare workloads for the operating system upgrade, the results of the migration process vary based on the type of system from which you are upgrading and the workload-management licensing you have secured for use with SLES 11. Likewise, the workload-management options available post upgrade vary based on licensing.