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FusionReactor Agent

Why do I need to install the FR Java Agent?

Installing FusionReactor will give you additional powerful capability and new ways to analyze your metrics as well as log data.

The FusionReactor agent can be used to monitor Java and ColdFusion to deliver current and historical information about web transactions, memory & CPU usage, database query performance, code – memory and thread profiling, garbage collection data and automated error detection plus much more.


FusionReactor provides:

  • detailed information about your application's performance, including memory and CPU usage, slow request analysis, and more.

  • an alerting system to help you proactively identify and resolve performance issues before they become critical problems.

Installing FusionReactor helps improve the stability, reliability and performance of your Java applications, making sure they meet the demands of your users.


FusionReactor is a Java agent (jar file) which contains most of the functionality and a native debugger library which provides the event snapshot, debugger, and heap analysis features.

Getting started

Step 1: Create a directory for FusionReactor.

To begin installing FusionReactor onto your application server, first create a directory structure for FusionReactor files to be stored within.

Platform Path
Windows C:\\FusionReactor\Instance\myInstance
Linux /opt/fusionreactor/instance/myInstance
MacOS /Applications/FusionReactor/instance/myInstance

Learn more

Create directory

Step 2: Download files into folder

Download the fusionreactor.jar file and Debug library, here

With your directory structure configured, you can now place the fusionreactor.jar and debug lib into your newly created instance directory.


Ensure the user running your application server can read and write to this directory, otherwise you may be unable to start the application server or save any information such as logs or configuration to disk.

Step 3: Stop your application server/Java process.

JVM arguments for your application server are only read when the server / JRE (Java Runtime Environment) is started. For this reason we recommend that you stop your application server before adding or modifying any of your JVM arguments.

Step 4: Configure arguments.

In order to run FusionReactor, you must add JVM arguments to initialize the FusionReactor installation files.

Step 5: Start your app server/Java process.

With your JVM arguments now modified, FusionReactor should start within the Java process.

Learn more

Start app server

Step 6 (optional): Access the FR Agent UI in On-Premise.

Access the On-Premise implementation to discover useful information about your application server.

Ingesting data with the FR Agent


Visualize your data

With FusionReactor Cloud, you can diagnose both live and historic issues with our powerful metrics engine and dashboards.

Need more help?

Contact support in the chat bubble and let us know how we can assist.