WLM is most effective managing applications that are CPU-bound. It automatically adapts system or partition CPU resources (cores) to the demands, SLOs, and priorities of the running applications. It adjusts the CPU allocation of a group of processes known as a workload, basing adjustment on the current needs and performance of the applications in that workload.
You can also use WLM to manage workloads to divide resources within a single HP-UX instance. In this case, you manage SLOs for workloads based on PRM-based pSets or FSS groups. These workloads are usually referred to as "workload groups." WLM can manage real memory and disk bandwidth within an HP-UX instance, although not in response to SLO performance. Disk bandwidth can be statically allocated.
WLM supports the logical CPU (Hyper-Threading) feature for pSet-based groups. Hyper-threading is available on certain processors starting with HP-UX 11i v3 (B.11.31). Each core with Hyper-Threading enabled can contain multiple logical CPUs―or execution threads. WLM automatically sets the Hyper-Threading state for the default pSet to optimize performance. When new pSets are created, they inherit the Hyper-Threading state that the system had before WLM was activated. Cores can be moved from one partition to another and will take on the Hyper-Threading state of their destination pSet. You can override the default state for cores assigned to a specific pSet-based group; you can also modify the Hyper-Threading state of the system.
You can use WLM within a whole server that can be clustered in an HP Serviceguard high availability cluster, Extended Campus Cluster, Metrocluster, or a Continentalcluster configuration. You can also use WLM on an Integrity VM host and within any individual Integrity VM (guest).
With HP-UX WLM, you define objectives with a priority, which you then assign to a WLM workload. You can set objectives to meet utilization goals or metric goals. Also, you can set objectives to provide a fixed allocation or a shares-per-metric allocation, which for example, can give a workload 2% of the CPU resources for each process in the workload.
You can assign one or more SLOs to a workload. The ability to assign multiple SLOs is helpful for workloads that require more than one SLO to accommodate a "must meet" goal and optional, lower priority stretch goals.
You can monitor your SLOs through either a command-line interface or a graphical interface.
Automatic CPU allocation
HP-UX WLM automatically allocates CPU resources to maintain application performance during changing system conditions and fluctuations in workload demand.
Secure Resource Partitions
HP-UX WLM supports Secure Resource Partitions, which combine HP-UX 11i V2 security capabilities with the resource management capabilities of HP-UX WLM. This combination allows you to consolidate multiple applications within a single operating system image, providing them dedicated resources plus operating system level security from other applications.
nPartitions are hardware-based partitions, each running its own instance of the HP-UX operating system. With Instant Capacity (iCAP) software (formerly known as iCOD software) installed on each nPartition, WLM can simulate movement of cores by deactivating a core on one nPartition then activating a core on another nPartition, moving the resources to where they are most needed. You can use virtual partitions within nPartitions.
Virtual machines, like virtual partitions, are created by software. Virtual machines emulate generic servers, and therefore can offer sub-core and shared I/O capabilities. Each virtual machine runs its own operating system. HP Integrity Virtual Machines can be used within hard partitions.
HP-UX WLM integrates with numerous products to allow you to better manage your systems. For example, you can use WLM with:
With this option, you can activate and deactivate cores, optimizing the amount of time these resources are used to meet the needs of your workloads. You purchase a codeword to obtain rights to use certain Instant Capacity cores for a preset amount of days. This codeword is applied to a system so that you can turn on and off any number of these cores as long as your prepaid amount of temporary capacity days has not expired. WLM supports TiCAP version 6 or later.
For information on other products with which WLM integrates, see the Integration appendix in the HP-UX Workload Manager User`s Guide.
Note:
As of WLM A.03.01, PRM is no longer included with the WLM bundle. If PRM C.03.00 or later is already on the machine on which you must install or upgrade WLM, you can continue to manage FSS and pSet-based workload groups just as if PRM had been installed with WLM. If you are installing WLM for the first time on a machine, you can use a strictly host-based configuration (no FSS or pSet workload groups). However, to manage FSS and pSet-based workload groups, you must install PRM (C.03.00 or later) separately. With your purchase of WLM, you are entitled to a PRM license. For information on receiving the PRM license, contact your regional licensing service organization.
