Glossary

active mode

An HPjmeter JVM agent that is part of an open console session and is collecting data from the

 

JVM and application and is sending it to a console.

agent

A module that represents HPjmeter in your environment. HPjmeter provides two types of

 

agents, a node agent and a JVM agent.

Batch mode

An HPjmeter JVM agent that is installed, configured, and is collecting data, but is not connected

 

to a console and is not part of a session. The collected data is stored in a file on the managed

 

node that you can open later from the console.

BCI

See bytecode instrumentation.

bytecode

Instrumentation of Java bytecode inserts a special, short sequence of bytecode at designated

instrumentation

points in the Java classes of an application to facilitate runtime analysis of those classes during

 

monitoring.

cached session

A session created when a running JVM terminates on its own, or when you close an active

 

session. The data in a cached session is available for analysis, but it is no longer connected to

 

a running JVM and is no longer collecting additional data.

call graph

Displays the capture of “call” relationships between the methods. The nodes of the call graph

 

represent the program methods, while the directed arcs represent calls made from one method

 

to another. In a call graph, the call counts or the timing data are collected for the arcs.

call graph trees

Call graph data presented in a collapsible and expandable tree hierarchy. See also call graph.

clock time

The time as measured by an external independent clock.

confidence

The measure of reliance or assurance that HPjmeter diagnosed the situation correctly.

confidence

The HPjmeter graphical representation of probability that the displayed values are correct. As

interval

the number of samples taken increases, the probability increases.

console

The main window containing the menu and button controls for monitoring live applications

 

and analyzing captured data.

Console filters

The Session Preferences window allows you to specify the classes to measure when you

 

open a session with a JVM agent. For details, see Controlling Data Collection and Display

 

(page 36)

CPU time

Time spent by any central processing unit (CPU) to execute a thread.

CPU virtual times

Times when a thread is runnable, but not necessarily running. Depending on the actual hardware,

 

operating system, and Java VM, this time may also include I/O time, but generally CPU virtual

 

times are a good approximation of real CPU time consumed by the application.

creation rate

The calculated rate at which new objects are occupying the heap.

dormant mode

An HPjmeter JVM agent that is installed and configured, but is not part of an open console

 

session and is, therefore, not collecting data from the JVM and applications and is not sending

 

data to a console.

dynamic attach

In HPjmeter, the ability to find and connect to a running JVM on a machine that has the HPjmeter

 

node agent running, but the JVM was started without using HPjmeter options.

eden

That part of the heap where new and/or short-lived objects (the young generation) are created

 

and used.

ephemeral port

a temporary port number assigned from a range of numbers designated for this purpose.

number

 

exclusive times

The accumulated total times used by a method, but not including the time used by the methods

 

that were called from it.

filter

To exclude the measurement of specified classes. HPjmeter provides two methods to control

 

how information is collected and displayed, JVM agent filters and console filters. For details,

 

see Controlling Data Collection and Display (page 36)

garbage collection

The process of automatically freeing memory by removing objects that are no longer referenced

 

by the program.

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