The following figure simulates pie charts in the Teradata Viewpoint Workload Monitor portlet to illustrate the process of assessing which workloads best qualify for SLG tier assignment.
Pie charts in the Workload Monitor portlet do not show allocation group or workload CPU consumption details for the L, M, H, R, or System performance groups. Because the DBA does not need to maintain those constructs in SLES 11, they can be discounted during migration.
The left side of the figure lists the workloads associated with the allocation groups on the right side. The relationship between workloads and allocations groups is indicated by the parenthetical number following each workload and allocation group listing. For example, the ETL_Priority and MSI_Medium workloads are associated with the User_Medium allocation group, as indicated by the (9) following each listing.
Actual pie charts in the Workload Monitor portlet do not contain the parenthetical numbers indicating workload-to-allocation group relationship. The figure has been enhanced with these components to illustrate the process of assessing which workloads best qualify for SLG tier assignment. You can, however, ascertain workload-to-allocation group relationship in the Workload Designer portlet, on the Workload Mapping tab.
Beside each workload listing, the figure displays the peak CPU usage percentage; likewise, the relative weight percentage is shown beside each allocation group listing.
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. You can use either source for relative weight information when completing the steps of the pre-migration process.
Following the recommended process for assessing which workloads best qualify for SLG tier assignment, the first step is to eliminate all tactical workloads from consideration. In this example, the first step excludes all workloads with a parenthetical designator of 5. The next step is to eliminate all workloads that are not business-critical. For this example, assume that all workloads are critical to the business. Likewise, assume that all workloads have a service level goal of less than 10 seconds. Given these facts, all remaining workloads are still possible candidates for the SLG tier, leaving the following as criteria for making a decision:
- The expected run time and the resource demands of the work destined for the workload
- The ratio of workload CPU consumption at peak processing times to relative weight of the allocation group associated with the workload
Given the high CPU usage value for workload MSI_Long, at 44%, eliminate it from consideration, leaving the following workloads to assess:
Assuming that all remaining workloads have a short run time, the final assessment criterion to apply is ratio of workload CPU consumption at peak processing times to relative weight of the allocation group associated with the workload. Given that workload CPU consumption should be lower than the relative weight of the associated allocation group, only the following workloads qualify for SLG tier assignment:
- DBA_Ctl: This workload maps to allocation group 6 with a relative weight of 15%, yet the workload consumes only 1% of the CPU.
- CRT_Short: This workload maps to allocation group 7 with a relative weight of 10%, yet the workload consumes only 8% of the CPU.
- MSI_Very_Short: This workload maps to allocation group 7 with a relative weight of 10%, yet the workload consumes only 3% of the CPU.
- MSI_Short: This workload maps to allocation group 8 with a relative weight of 7%, yet the workload consumes only 4% of the CPU.