HPjmeter 4.2 User's Guide

hot spot A section of code, typically a method, with a higher-than-normal level of execution or access
requiring high CPU usage.
inclusive time The accumulated total time used by all invocations of the method and all methods that were
called from it directly or indirectly.
inlining Replacing a call to a function with an instance of the function; usually done at compile time.
Java Management
Extensions
See JMX .
JMX™ Java Management Extensions. API for managing and monitoring applications, devices, services,
and JVMs. For API specifics, see the Java Community Process web: Java Management Extensions
(JMX) Specification (JSR3) and JMX Remote Specification (JSR160).
JVM Java Virtual Machine
JVM agent A module running on each managed node that collects data and sends it to the node agent,
which sends it to the console.
JVM agent filters
The include and exclude options to the JVM agent allow you to filter metrics by class name.
For details, see Controlling Data Collection and Display (page 36)
JVMPI JVM Profiler Interface
JVMTI JVM Tool Interface
lingering objects accumulated live objects that clog the heap, creating memory leaks.
lock contention The summary time measured from the moment the thread requests a Java lock until the lock
is actually granted.
Lock Delay The time elapsed between the moment a thread tries to acquire a lock and the time the thread
enters the monitor.
managed node A computer on which the HPjmeter node agent and JVM agent are installed.
memory leak HPjmeter uses the long term linear upward trends in the heap size after garbage collections to
calculate the likely presence of memory leaks. See How Memory Leak Detection Works (page 189)
metadata Objects needed by the Java interpreter and for reflection in garbage collection.
method A function defined in a class. Unless specified otherwise, a method is not static.
method call count The number of times each function (method) of the program was called during a run.
method clock
time
The actual time spent in each of the methods of the program.
metric In this context, a mapping that associates numerical values with static or dynamic elements
such as program functions, variables, classes, objects, types, or threads.
node agent A process that manages communication between JVM agents and a console. Node Agent
(page 13)
old generation Objects in the heap that have survived a successive number of garbage collections, and have
been moved to the old space in the heap.
package A group of types. Packages are declared with the package keyword.
reduction Accumulating data during tracing such that consecutive calls from the same caller to the same
callee increase the recorded time value for a call.
scavenge Incremental, lightweight garbage collection of primarily short-lived objects in order to free
space.
scope The breadth of view across thread-based profile data. HPjmeter lets you look at a single thread,
a group of threads, or the entire application.
service-level
objective
service-level objective. A service-level objective (SLO) partitions a service-level agreement (SLA)
into metrics and operational information to enforce and/or monitor the SLA.
session An open, live connection between an console and a JVM agent running on a managed node.
An open session has associated with it a set of metrics, filters, and alerts that are configured
when you open the session.
severity The measure of the expected impact of the detected situation on the application stability.
SLO See service-level objective.
200 Glossary