HPjmeter 4.2 User's Guide

• Viewing the Application Load (page 40)

• Checking for Long Garbage Collection Pauses (page 40)

• Current Live Heap Objects (page 129)

Heap Usage Notification

It can be useful to change the heap usage threshold in order to observe the heap structure at the

selected usage point.

You can also set this threshold to notify you when heap usage exceeds your maximum or

minimum expectations for the application.

By default, this notification is enabled in Session Preferences, but is turned off in the Alert

Controller until you turn it on. Once turned on, this alert activates when heap usage reaches the

default value of 10 MB or more .

For example, if you expect that your application should never consume more than 100 MB of

heap for a target period of time, set the threshold fields for heap size and time sustained, and

check that the alert is enabled. If the set values are exceeded, an alert is generated and recorded

in the alert log. An alert notice is posted on the console.

Double-click on the alert to display the Heap Monitor. In this visualizer, you can see the memory

allocated to the heap compared to usage over time, and including indicators for garbage collection

events and their duration.