Kevin Gee
Solution Architect, Enterprise Systems and Security, Pellera Technologies (formerly Mainline Information Systems)
IBM Power Systems Champion since 2019
The new IBM Power11 line of servers introduce new capabilities to improve your performance for workloads that already shared processor pools (SPPs): Resource Groups. This allows processor, memory, and I/O resources to be combined to improve resource affinity. They are simple, efficient, and provide more control, and will boost performance across the system. This idea isn’t new, it’s now significantly simpler to use.
Recap: Shared Processor Pools
Remember the purpose of Shared Processor Pools (SPP) on IBM Power: To allow multiple partitions to share CPU resources efficiently while controlling total consumption, which in turn helps reduce licensing and hardware costs.
SPPs enable partitions running AIX, IBM i, or Linux to dynamically use unused capacity from the pool, support workloads with fluctuating CPU needs, and ensure that workloads do not impact others outside the pool by capping CPU usage. SPPs are often used to reduce the cost of application licenses that use just a subset of the entire server. For example, if every LPAR using Oracle needs a combined 7 cores on a 40-core Power9 or Power10 system, a pool can be created to allow those partitions to share the computing power of 7 cores, and no more. Or, you can limit the number of cores you’ve assigned to a set of developers who are building test environments. This is great for proof-of-concepts and multi-tenant lab environments to cap a team’s resources so that they don’t step on others.
However, shared processor pools lack any sort of processor affinity, so you don’t get any of those benefits, and the name reflects, they only apply to processors.
The Advantages Resource Groups Provide
Resource Groups take this idea further by grouping both shared and dedicated partitions onto a set of processor cores, memory regions, and I/O adapters, enhancing affinity, workload isolation, and flexibility. These don’t replace shared processor pools – they complement each other.
- Improve Performance: Resource Groups help workloads run faster by keeping them close to the resources they use most often, reducing latency and improving cache utilization.
- Group Workloads Easily: Resource Groups combine multiple applications into a single Resource Group for easier management.
- Better Affinity and Isolation: Resource Groups ensure shared processor workloads use specific cores, improving performance and providing better separation between workloads. This is great for multi-tenant environments.
- Work with Shared Processor Pools: Combine Resource Groups together with Shared Processor Pools to balance cost, performance, and control.
- Close to Dedicated Performance: Preliminary tests at IBM show Resource Groups can deliver performance close to dedicated processors, even on large systems, with internal tests showing improvement up to 25%. This may lower costs further through needing even fewer cores.
- Flexible Configuration:
- Resource Groups can include both shared and dedicated partitions.
- You can move powered-off partitions between groups.
- Adjust the cores assigned to each group dynamically as needs change.
- Each group has its own Shared Processor Pools.
- Resource Groups can be configured with a mix of general-purpose cores for AIX, IBM i, Linux, including VIOS.
- Visibility and Control:
- Clear usage metrics in the management console for Resource Groups and Shared Processor Pools.
- Dynamic Platform Optimizer (DPO) can run across the entire system or within a specific Resource Group.
- When using Live Partition Mobility (LPM), you can select the target Resource Group.
- Both the hardware management console (HMC) and PowerVC software provide policy-based management of Resource Groups.
- Future-Ready: Resource Groups are fully compatible with the Power Enterprise Pools 2.0 offering.
Take an example of a critical ERP system, with dev/test and analytics workloads alongside production. Shared processor pools are probably already in place optimize licensing. Resource groups keep the production workloads on the same set of cores or on the same I/O resources, and you shift all of the lower-priority workloads into separate groups.
Where Resources Groups Shine: Five Real-World Use Cases
Here are five use cases where Resource Groups combined with Shared Processor Pools provide a benefit. In four of the five cases, the original server might only use a single, default shared processor pool.
(Note: the images come from the new “IBM Power11 E1150 Introduction and Technical Overview” RedBook, available here.)
1. Consolidate Multiple Lines of Business and Assign their Own Resources
Consolidate workloads with better isolation and performance. In this example, a second shared processor pool is created, and the groups are assigned their own set of resources.
Figure 1. Two business groups assigned their own resources.
2. Isolate Production from Test/Development
Keep test and dev LPARs in the default group while shielding production workloads on their own set of resources. In this example, a second pool is created, and two resource groups are created, with the critical production LPARs placed into their own pool and group. Note that licenses for App1 and App2 and their respective databases will need to be maintained across both pools.
Figure 2. Isolate Prod from Dev and Test.
3. Improve App Performance by Grouping Tiers
Place a specific application and its database in the same resource group on its own set of resources for faster communication and better performance. The other LPARs are put into a different pool and resource group.
Figure 3. Group DB and App together.
4. Server Consolidation While Maintaining System-Level Isolation
Combine multiple servers into a single Power11 while logically isolating workloads to secure and manage each group independently.
Figure 4. Consolidate systems into their own group.
5. Map Existing Processor Pools Into Resource Groups
Map multiple Shared Processor Pools into a Resource Groups for each.
Figure 5. Map each SPP to a separate resource group.
The Resource Group Advisor (RGA)
IBM offers a free web-based Resource Groups Advisor (RGA) to help customize your setup before deploying. The RGA is available here: https://www.ibm.com/it-infrastructure/resources/resource-groups-advisor.
Summary
Resource Groups help you optimize performance, control, and cost across your IBM Power11 environment, making system management easier and workloads faster.
To learn more about Resource Groups and IBM Power11, please contact your Pellera representative.