JMX stands for Java Management Extensions. It’s a standard API that enables management of monitoring and performance data in applications. JMX can be used to monitor any Java process, including Tomcat, Jetty and other servlet containers, as well as any third-party libraries or services that you use. In this article, you will learn about basic usage of JMX in production environment with simple examples. If you are new to monitoring and performance management, check out our blog post
What is JMX?
Java Management Extensions (JMX) is a standard API that enables management of monitoring and performance data in applications. It is also known as the Java Virtual Machine (JVM) management interface. Applications that provide JMX data are said to be “managed”. JMX is built in to the Java Virtual Machine. JMX is used to monitor any Java process, including Tomcat, Jetty and other servlet containers, as well as any third-party libraries or services that you use.
Point of JMX in production
One of the key points of JMX in production is monitoring Health of your application. Health monitoring is a simple and easy to use solution for identifying and fixing issues with your application. Once Health monitoring is enabled, you will receive alerts when something goes wrong, such as a process is down, or a resource is very busy.
Another important point of JMX in production is Tuning. You can use JMX to get data metrics, such as how much memory your application is using, the number of connections it has, the number of requests it is receiving, and so on. You can then use this data to tune, or adjust, your application for optimal performance.
How to use it?
The first step is to enable JMX in your application. You can do this by adding the following line in your application’s “server” or “host” section in the server.xml file.
The next step is to add the JMX endpoint to your application. The following code snippet shows how to do this.
The final step is to use a JMX client, such as JMeter, to access the JMX endpoint of your application and get metrics. In JMeter, you can do this by adding a “HTTP Test” rule. Set the “URL” to “jmx://hostname>:port>/jmx/”.
How to configure JMX?
JMX can be configured during application startup with the help of java. Management. ManagementFactory class.
Let’s take an example to understand how to configure JMX. Create a new Maven project with below dependencies.
To enable JMX in application, you need to add below dependency in your pom.xml file. dependency> groupId>org.apache.tomcat/groupId> artifactId>tomcat-jmx-admin/artifactId> version>8.5.31/version> /dependency>
Let’s explore the code of above configuration.