HPjmeter 4.2 User's Guide

• Interactive call graph with call count, or with CPU or clock time, if available

• Per thread, per thread group, or per process display

• Allocated and residual objects with object reference graph

• Comparison capability for performance improvement tracking

HPjmeter provides these metrics for garbage collection (GC) analysis:

• Details and graphical display of object creation rate, changes in cumulative memory allocation

and in heap usage as related to GC events and types, and duration of GC events in the

recorded time period.

• Detailed summaries of GC activity and system resource allocation, along with other system

and JVM runtime and version data.

HPjmeter also provides these notification functions:

• Set notification thresholds for abnormal thread termination, excessive compilation, expected

out-of-memory error, and memory leak rates.

• Set notification thresholds for levels of heap usage, process CPU, and system CPU.

• Enable or disable notifications.

• Change notification thresholds in real time to efficiently monitor targeted events

Concepts

HPjmeter contains these major components:

• The console – the primary control window where monitoring sessions are initiated and

controlled and where data files are opened and listed for access. The console presents data

in viewing windows that contain controls and functions specific to the data type and the

activity of the user.

• The monitoring agent – represents HPjmeter on each managed node. The agent has two

subcomponents:

— The JVM agent: Each running JVM has an associated JVM agent that collects data and

sends it to a node agent, which sends it to the console.

— The HPjmeter node agent: Each managed node has a node agent that communicates

between the console and JVM agents.

JVM Agent

The JVM agent uses standard Java profiling interfaces (JVMTI and JVMPI) and a standard

monitoring and management interface (JSR174) to collect data from a running application and

to provide metrics to help detect and fix problems in that deployed application.

The JVM agent shares a process with a running JVM and forwards data through the node agent

to a console. Multiple consoles can connect to each of the multiple node agents on a managed

node. However, only one console and node agent can maintain an active session with a specific

JVM agent at any given time.

Node Agent

Node agents manage communication between JVM agents and consoles. The preferred way of

using node agents is to start the node agent as a daemon as root on each managed node.