Workload Designer has been updated to make it easier to understand and configure how resources are assigned to workloads. TASM 14.0 onwards SLES 11 uses a new method of workload resource allocation that is intended to simplify the process conceptually and procedurally. This post describes the new workload resource allocation user interfaces and how they can be used to perform some basic resource allocation.
The first point of clarification is how resource percentages in the interface are actually interpreted. Percentages that you specify for allocating resources are soft limits. With soft limits you specify the share of resource that you desire, but that level can be exceeded if there are unused resources available.
Workloads are used to manage the resources available to queries/requests. Workloads have classification criteria to determine which queries are managed by the workload. Classification criteria are attributes of the query that you want to be present such as queries from a specific username or queries with a given estimated processing time.
Workloads are associated with a virtual partition and a management method to specify how resources are assigned to the workload.
Virtual partitions are used to divide system resources among groups of workloads.
Each workload is assigned to one of the available VPs. The workloads in a VP are limited (see Soft Limit definition above) to the resources allocated to the VP. Each system can have up to 10 virtual partitions.
For example, multiple virtual partitions could be used if you want to allocate 60% of the system resources to the finance department workloads and 40% of the resources to the human resources department workloads.
Management methods define the general priority of a workload within a virtual partition, and how resources given to a virtual partition will be allocated to that workload.. There are three different types of management methods: Tactical, SLG Tier, and Timeshare.
Tactical workloads have the highest priority and are given access to all of the resources available in the associated virtual partition. Any resources not consumed by tactical workloads are then made available to SLG Tier workloads.
SLG Tier workloads are allocated percentages of available resources. There can be up to 5 tiers with each tier consecutively receiving fewer resources than the tier above as the workloads in each tier consume resources. Percentage allocation is relative to workloads in the same tier with an unallocated resources category to specify the resources that will be passed to the next tier. Any resources not consumed in the SLG Tiers are passed to the Timeshare workloads.
Timeshare workloads are automatically assigned resources relative to their assigned access level. The access levels are Low, Medium (2 times the resources of low), High (4 times low), and Top (8 times low). It is assumed that the majority of workloads will use the Timeshare management method.
Use planned environments to define different management settings to be used during specified time periods or based on different operating conditions. This feature is not new to Workload Designer but adds an additional layer of flexibility when configuring resource allocations. Planned environments are configured on the States screen.
Using the concepts defined above, you can perform some basic configuration and resource allocation. The following is just one of many ways to allocate resources.
Only one virtual partition is required and it is created by default when you create a new ruleset. When only one virtual partition is present, it is allocated 100% of the available resources. If you want to divide the available resources between different departments, countries, or whatever, you can create additional virtual partitions. Initially, the easiest way to proceed is to keep things simple by using only the default virtual partition.
The virtual partitions interface is located in the Workloads section of Workload Designer, on the Virtual Partitions tab. From there you can add, remove, and rename partitions, see which workloads are assigned to each partition, and drag workloads between the partitions.
Virtual Partitions Image: Stick with the default virtual partition, named Standard, or add additional partitions.
If you create multiple virtual partitions, you can allocate resources to the partitions using the Partition Resources tab. Drag the boundaries between the partitions to change the allocations. If there is more than one planned environment, the interface displays one row for each environment so that you can perform additional tailoring of the partition allocations, if necessary.
Partition Resources Image: Allocate resources to the virtual partitions when you have multiple partitions
Now that the virtual partitions of resources have been defined, workloads can be added to the partitions to consume the resources. Workloads are created in the Workloads section of Workload Designer, on the Workloads tab.
Workload Details Image: Use the Workload Details screen to perform some basic configuration
The workload details screen is similar to the previous versions but with a few different options. From the perspective of configuration, the main differences between this and previous versions of Workload Designer are the ability to:
If there is only one virtual partition, workloads are automatically assigned to the partition, otherwise, select a virtual partition. When multiple partitions are present, you may find it easier to create workloads with the default partition and then use the Virtual Partitions tab to drag the workloads to the desired partition.
Each workload must be assigned a management method at the time it is created. If you are not sure which management method you need, use the general purpose Timeshare method. The Medium access level of the Timeshare management method is a reasonable default location for a new workload, and it easy to make adjustments later, if necessary. The workload details screen allows you to switch between the management methods but it does not give access to details such as allocation percentages, access levels, or how other workloads in the same virtual partition have been configured. If you know that you want to change the management method or fine-tune related settings, it is recommended that you use the Workload Distribution screen.
Now that virtual partitions have been created and workloads have been assigned to the partitions, you can fine-tune resource allocations. The Workload Distribution screen in the Workloads section of Workload Designer represents a top-down flow of resources to help visualize the priority of workloads.
Workload Distribution Image: See allocations relative to one another and fine-tune settings
At the top of the screen is the name of the virtual partition you are viewing and the percent of system resources that have been allocated to the partition (more on the planned environment in a minute). Because each workload is assigned to one virtual partition, switching between partitions will display different sets of workloads below.
Tactical workloads get first access to the resources in the partition. With the exception of the WD-Default workload which must remain in the Timeshare section, any workload can be dragged to the Tactical section and no additional configuration is required.
After the resource needs of the tactical workloads have been satisfied, the remaining resources flow to the first SLG Tier. Any workload (other than WD-Default) can be dragged to an SLG Tier. Once in a tier, the right edge of the workload can be dragged to allocate more or less resources. The rightmost region in a tier shows the amount of resources from the tier that will be passed to the next tier/Timeshare. Since this is a basic introduction, I will not get into the specifics of how to interpret the percentages in this post (if people show interest I may follow up in another post).
Resources continue to flow down until they enter the Timeshare section. Here, the remaining pool of resources is allocated by access level. Any workload can be dragged to a Timeshare access level (i.e. Top, High, Medium, Low) with no additional resource configuration required for the workload.
The process and screens described above are the basics for resource allocation but when you start feeling adventurous, you can play around with planned environments. Planned environments give you more flexibility to tailor allocations based upon known operating conditions but it also multiplies the complexity of configuration because virtual partitions and workloads can have different settings in each planned environment. So, if you have 2 planned environments and 3 virtual partitions with 5 workloads in each virtual partition, you would have 6 different Workload Distribution screens/combinations to configure to verify the settings of the 30 workload settings represented in those views. If you have 5 planned environments then… eek!
The good news is that you are not required to have multiple environments and there is a configuration shortcut you can use. The easiest way to start is to configure all virtual partitions, workloads, and management method percentages and access levels before adding additional planned environments. When a new planned environment is created, it copies all resource allocation settings from the default (named "Always") planned environment. At a minimum, this can give you a starting point that is based on an existing, intended configuration.
To get started:
When you are ready for more granular control over resource allocation:
That's all for now!
I have just started working with Teradata/Viepoint.
My Concern is -
Is vproc alert shows in Alert Viewer may degrade query performance?