HPjmeter 4.2 User's Guide

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
Instrumentation of Java bytecode inserts a special, short sequence of bytecode at designated
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
interval
The HPjmeter graphical representation of probability that the displayed values are correct. As
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
number
a temporary port number assigned from a range of numbers designated for this purpose.
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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