Using the Java Application Page

The Java Application page provides a high-level overview of the application that was running when this recording was made.

This page contains per-thread estimates of I/O time, blocked time, class loading time, and memory allocation presented in both tables and graphs.

You can set the layout orientation by clicking on the Horizontal Layout or Vertical Layout icons.

Using the Java Application Page: Selections and Aspects

Use the drop-down menus at the top of the page to choose a selection and aspect if desired. Data from other pages can be saved to the selection drop-down menu by dragging an area of a chart (or selecting data from a table) and choosing Store Selection or Store Selection and Set As Focused Selection from the context menu.

The following controls provide additional behavior:

Show concurrent: Show all events concurrent to the selected aspect.
Contained: Only show events that are fully contained in the time range from the active selection aspect
Same threads: Only show events in threads related to the active selection aspect.
Time Range: Zoom to time range on relevant places on the page, or clear the time range zoom.

Using the Java Application Page:Tables and Graphs

Table columns are labeled as follows:

Thread: The name of the thread.
Profiling Samples: The number of method profiling samples for this thread.
Total I/O Time: An estimate of the total time a thread is busy with I/O. The actual total may be higher.
Total Blocked Time: An estimate of the total time a thread is blocked by a monitor. The actual duration may be higher.
Class Loading Time: An estimate of the total time a thread has spent loading classes. The actual duration may be higher.
Total Allocation: An estimate of the total allocation. This is not an exact value.
Throwables: The number of created throwables.

You can select any of the following to be displayed on the graph:

Halts: Periods where the JVM has halted execution of user code, for example due to garbage collection.
Machine Total: CPU used by all processes on the machine.
JVM + Application: Total CPU used by the JVM process.
used Heap: Total memory allocated by objects on the heap.
Method Profiling: The number of profiling samples. The color represents the distribution of the top stack trace frames (red = most samples in a few methods, yellow = samples are evenly distributed).
Total Allocation: An estimate of the total allocation. This is not an exact value.
Throwables: The number of created throwables.
Thread Activity: Thread activity lanes. Use the context menu to configure individual lanes.

Using the Java Application Page: Configuring Rules

You can set configuration attributes for the rules associated with this page by clicking the Edit Configuration icon.

The following options are available:

Application Halts

Application Halts Info Limit: Ratio between application halts and execution time within the time window needed to trigger an info notice.
Application Halts Warning Limit: Ratio between application halts and execution time within the time window needed to trigger a warning notice.
Application Halts Time Window Size: Time window used for evaluating the rule

High JVM CPU Load

JVM CPU Usage Info Limit: The amount of CPU used by the JVM needed to trigger an info notice.
Minimum CPU Load Period: Minimum CPU load period to trigger a warning.
Missing Sample Limit: Minimum missing samples to trigger a warning.

Parallel Threads

Sampled Threads Ratio Limit: Ratio between sampled threads and hardware threads needed to trigger a warning.
Min Used CPU Ratio: Minimum used CPU Ratio for the application to not be considered idle.
Short Recording Limit: Minimum length of recording to be considered
CPU Window Size: Sliding window size used to calculate CPU Usage
Min Total Sample Count: Minimum number of samples in the recording required to evaluate this rule
Min Sample Count Per Thread: Minimum number of samples in a thread required to consider this thread as sampled