Measure Reference Manual

For a description of the command interface, see Chapter 2: MEASCOM Commands (page 35)
and Chapter 3: Entities and Counters (page 136).
• The programmatic interface is a set of callable procedures. By calling these procedures from
your applications, you can access all Measure functions. For example, you can write an
application that configures a measurement, starts the measurement, stops it, and writes the
data to a file for analysis. For a description of the programmatic interface, see Chapter 4:
Measure Callable Procedures (page 373).
A sample measurement that shows the command interface appears later in this section. But first,
you need to know two basic terms: entity and counter.
Entities and Counters
An entity is the system resource to be measured. The Measure performance monitor recognizes
the types of entities in Table 2: Measure Entity Types (page 136).
In this manual, a class of entities (such as processes or disks) is called an entity type. The identifier
for a specific individual entity in a class is called an entity specification. Thus, FILE is an entity type,
and \NY.$SALES.Q1.JAN is an entity specification.
Each entity type is associated with a predefined set of counters. A counter is a programmatic
structure that collects a specific type of performance data. For example, the CPU entity type has
a SWAPS counter, which counts the number of swaps that occur in each measured CPU.
The system software associated with each supported entity type includes built-in calls to Measure
procedures. When a measurable event occurs, the controlling software calls a procedure that
increments the appropriate counter.
You can add custom instrumentation to your measurements by defining your own counters and
using Measure procedure calls in your programs to increment those counters. For example, you
can create a counter that is incremented each time a program executes a particular loop. Processes
that carry out custom measurements are identified by the entity type USERDEF, for user-defined.
The Three Steps of Measurement
The three steps of measurement are:
1. Configure the measurement.
2. Take the measurement.
3. Examine the measurement.
The next three subsections describe a sample measurement session using the command interface.
In this example, the commands you would enter are shown in boldface type. The Measure screen
displays are shown in regular type.
A measurement session that uses the programmatic interface instead of the command interface
follows the same basic operations, but the operations are implemented by procedure calls within
a program.
NOTE: The MEASCOM listings shown in the Manual are only examples and can be changed
without notice. They cannot be used for parsing of output. For parsing, use the SET REPORT FORMAT
STRUCTURED command.
Step 1. Configure the Measurement
The measurement configuration determines which entities are measured.
The first three lines of this sample measurement are:
21> MEASCOM
1+ ADD CPU 5
2+ ADD CPU 6
30 Introduction to Measure