WLMTK Overview: Using HP-UX WLM Effectively With Your Most Critical Applications

Executive summary

HP-UX Workload Manager (WLM) is a virtualization solution that helps you achieve a true Adaptive

Enterprise. As a goal-based policy engine in the HP Virtual Server Environment (VSE), WLM integrates

virtualization techniques—including partitioning, resource management, utility pricing, and

clustering—and links them to your service level objectives (SLOs) and business priorities. WLM

enables a virtual HP-UX server to grow and shrink automatically, based on the demands and SLOs for

each application it hosts. You can consolidate multiple applications onto a single server to receive

greater return on your IT investment while ensuring that end-users receive the service and performance

they expect.

WLM automates many of the features of the Process Resource Manager (PRM) and HP-UX Virtual

Partitions (vPars). WLM manages CPU resources within a single HP-UX instance as well as within and

across hard partitions and virtual partitions. It automatically adapts system or partition CPU resources

(cores) to the demands, SLOs, and priorities of the running applications. (A core is the actual data

processing engine within a processor, where a single processor can have multiple cores.) On systems

with HP Instant Capacity (iCAP), WLM automatically moves cores among partitions based on the

SLOs in the partitions. Given the physical nature of hard partitions, the “movement” of cores among

partitions is achieved by deactivating a core on one nPartition and then activating a core on another.

WLM is optimized for moving and balancing CPU resources across partitions. Using hosts as

workloads, WLM manages workload allocations while maintaining the isolation of their HP-UX

instances.

If you choose to manage workloads so that resources are divided and shared within a single HP-UX

instance, the workloads are based on PRM groups: Fair Share Scheduler (FSS) groups or groups

based on processor sets (pSets). Within a single HP-UX instance, WLM can manage CPU resources

along with real memory and disk bandwidth. (WLM does not manage real memory and disk

bandwidth in response to SLOs; you assign these resources statically rather than dynamically.) When

you configure WLM, you define workload groups and assign processes to them based on specific

applications, users, or UNIX® groups. You can also create your own criteria for placing application

processes in specific workload groups by defining process maps. In a process map, you map a group

to a script or command that gathers process IDs and causes the identified processes to be assigned to

the group. (The WLM SAP Toolkit, in conjunction with HP Serviceguard Extension for SAP [SGeSAP],

takes advantage of process maps, providing a script that enables you to place specified SAP

processes in specific workload groups managed by WLM.) Another way to assign processes to

workload groups is by assigning secure compartments to the workload groups. You create the secure

compartment with the HP-UX feature Security Containment. Secure compartments isolate files and

processes. WLM can then automatically allocate resources for these secure compartments.

Using WLM in combination with HP-UX Workload Manager Toolkits (WLMTK), you can quickly and

effectively deploy WLM for use with your key applications. The freely available WLMTK product

consists of several toolkits, each with example configuration files. Toolkits are currently available for:

• Oracle® databases

• Apache web server software

• BEA WebLogic Server

• SAP

• HP-UX SNMP agent

This paper discusses the toolkits available with WLMTK A.01.10.xx, which runs on PA-RISC servers

(HP 9000) running HP-UX 11i v1 or later or on PA-RISC or Intel® Itanium®-based servers running HP-

UX 11i v2 (B.11.23) or later.