Participating in Enterprise Workload Management

Enterprise Workload Manager™ (EWLM) is a systems service of the IBM® Virtualization Engine™. Virtualization Engine is a set of technologies and systems services that allow system administrators to access and manage resources across multiple platforms (z/OS®, AIX®, i5/OS™, Windows, Solaris and Linux). The EWLM systems service allows you to define business-oriented performance goals for an entire domain of servers across multiple platforms, and then provides an end-to-end view of actual performance relative to those goals.

For example, a multi-platform environment might include:

• A Web server tier running Windows
• An application server tier running AIX
• A database tier running z/OS

To ensure that work requests are performing as expected in this environment, you must be able to track the performance of those requests across server and subsystem boundaries. EWLM allows you to do that.

EWLM uses middleware that has been instrumented with the Open Group's Application Response Measurement (ARM) 4.0 standard. ARM 4.0 provides a set of interfaces that an application calls; these are then used by EWLM to calculate the response time and status of work processed by the application.

In a multi-tiered environment, what is perceived as one transaction may be implemented as many sub-transactions across several different applications. To relate the sub-transactions with one another, ARM 4.0 uses correlators. Relationships are established by passing the correlator of a parent sub-transaction to its child sub-transactions. The correlator for a parent sub-transaction, that is, a correlator that is passed from the sending application tier, is called a parent correlator. A correlator for its child sub-transaction is called a current correlator.

Ordinarily, applications that participate in EWLM use standard instrumentation based on the ARM 4.0 Java™, C or C++ language bindings. However, because applications that use the WLM enclave services are already instrumented, WLM provides support for EWLM through a set of new and enhanced enclave services.

The WLM support for EWLM is effective only if the ARM agent is enabled and an EWLM policy is installed. Operators can control the state of the ARM agent by disabling or enabling the function from an operator console at any time with the F WLM,AM command. Additionally, the current state of the ARM agent can be displayed by the operator command D WLM,AM. For more information, see z/OS MVS System Commands.

For more information on Virtualization Engine and EWLM, including using the ARM APIs to instrument an application, see the Information Center on the Internet at http://publib.boulder.ibm.com/eserver/v1r1/en_US/index.htm?info/icmain.htm

For more information on enclaves, see Creating and Using Enclaves.