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

See JMX .

Extensions

 

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

The actual time spent in each of the methods of the program.

time

 

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

service-level objective. A service-level objective (SLO) partitions a service-level agreement (SLA)

objective

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