IBM Enterprise Workload Manager Release 1

Chapter 1. IBM Enterprise Workload Manager Overview 13

These EWLM goal definitions are server and application agnostic. This means that hardware

and application upgrades can occur without requiring changes to the goals defined.

To prepare for developing a Domain Policy, the administrator should:

򐂰 Create a list of the instrumented applications to be managed in the EWLM Management

Domain. See “EWLM supported platforms and applications” on page 16 to identify

whether your application is supported in this release.

򐂰 Create a list of all the transaction types to be managed for each business application.

Assign a business goal and importance for each type of transaction based on your existing

SLA.

򐂰 Create a list of operating system platforms to be managed.

򐂰 Create a list of various processes on each of the managed platforms that will be

processing the transactional or non-transactional work and assign business goals and

importance.

򐂰 Group the transactions and processes based on the business goals and importance. This

will be the basis for the service class.

1.2.5 Instrumentation

Instrumentation provides the data to create the topology of a transaction, that is, what server

instances or application instances a transaction flows through. In a typical Web transaction,

for example “Buy Books,” the transaction starts at a Web server (edge server), flows to an

application server, then to a database server. Without instrumentation, the transaction would

look like three separate processes with three separate response times rather than one

transaction. This is key to EWLM, providing end-to-end topology views and statistics for

business transactions.

In order for EWLM to report on these transactions and potentially manage the domain based

on these statistics, Application Response Measurement 4.0 (ARM) has been implemented for

application instrumentation. ARM is an Open Group standard composed of a set of APIs that

can be used to collect response time information for enterprise applications. Currently there

are three types of applications instrumented with ARM 4.0: WebSphere Application Server,

DB2 UDB, and Web servers. ARM 4.0 supported middleware includes the following:

򐂰 DB2 UDB V8.2

򐂰 WebSphere V5.1.1

򐂰 WebSphere Plug-ins delivered with 5.1.1

For the correct plug-in releases, refer to the Web Servers section of the table at:

www.ibm.com/software/webservers/appserv/doc/v51/prereqs/was_v511.htm

򐂰 Independent IHS/Apache Web server ARM plug-ins

– Configures into IHS 2.0.42

Placed into the http serve/modules directory (minimum release tested)

Note: Customer-developed applications can be instrumented so that EWLM can

manage them. This requires using ARM 4.0, which is described in the next section,

“Instrumentation.”

Note: For applications that are not instrumented, EWLM provides process-based

management instead of transaction-based management.

14 IBM Enterprise Workload Manager

– Available from the Apache Web site

򐂰 Independent IIS Web server ARM plug-in

– Configures into IIS 5.0 and later

– ARM 4.0 support ships with IBM Virtualization Engine Suite for Servers

Let’s look at how ARM, EWLM, and instrumented applications work together to provide

end-to-end response times and application/transaction topology using correlation. Figure 1-7

has three EWLM managed servers and a domain manager in a EWLM domain. When a user

request is initiated, the transaction flows through the Apache, WebSphere Application Server

and DB2 middleware. The ARM instrumentation in each application layer is shown as a

arm_start_tran() and arm_stop_tran().

Figure 1-7 Transaction Correlation using EWLM, ARM, and Middleware

The arm_start_tran() call at each middleware layer indicates to the EWLM ARM

implementation the start of a transaction (or sub-transaction) instance, and therefore that

EWLM needs to record the transaction start time for the middleware service. The

arm_start_tran() call specifies ARM properties (also called filters) for the transaction instance

that the EWLM ARM implementation compares against service policy information to classify

the transaction instance to a particular transaction class and, consequently, a particular

service class. The service class, in turn, associates the transaction instance with a business

goal and relative importance to other work occurring in the EWLM domain.

The arm_stop_tran() call at each middleware layer indicates to the EWLM ARM

implementation the completion of a transaction (or sub-transaction) instance, and therefore

that EWLM needs to compute the response time for the transaction instance. The

arm_stop_tran() call also specifies a transaction completion status, such as succeeded or

Apache

arm_start_tran()

arm_stop_tran()

…..

EWLM ARM

Impl

Policy

User Request

{ARM

Corr #1}

Websphere

arm_start_tran()

…..

DB2 UDB

arm_start_tran()

arm_stop_tran()

…..

EWLM

domain

manager

EWLM ARM

Impl

EWLM ARM

Impl

Apache

data

data

Websphere

data

DB2 UDB

correlated

{ARM

Corr #2}

arm_stop_tran()