PureJ VM Inspection offers an easy to use, feature-rich, JMX-based and embeddable Java VM monitoring tool with a web-based user-interface.
The goal is to monitor and control any Java application in production environments without the overhead and security-risks of an external JMX console. This works with Spring-Boot, Java-EE or any other Java-App which supports the servlet-spec. PureJ VM Inspection is easy to configure, requires minimal dependencies, is extremely lightweight (no profiling, no databases) and offers the following features:
- System: memory-status, VM- and OS details, class-loader details
- MBeans: Browse all MBeans, show and change attributes, invoke operations
- Threads: Live threads overview with current status, stacktrace and total CPU/user times
- Statistics: graphical memory-, threads-, and load-statistics with chooseable periods
For spring-boot apps, add the VmInspectRegistrationBean to your @SpringBootApplication or any other @Configuration class:
@Bean
public VmInspectRegistrationBean inspect() {
return new VmInspectRegistrationBean();
}
Other web-apps can add the servlet to their web.xml:
<servlet>
<servlet-name>vminspect</servlet-name>
<servlet-class>com.purej.vminspect.http.servlet.VmInspectionServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>vminspect</servlet-name>
<url-pattern>/inspect/*</url-pattern>
</servlet-mapping>
For non-webapps, VM inspection can be enabled using the internal lightweight standalone HTTP server:
new VmInspectionServer(8080);
Alternatively, non-webapps, can also use the VM inspection servlet with an embeddable web-server such as for example Jetty:
Server server = new Server(8080);
ServletContextHandler handler = new ServletContextHandler(server, "/inspect");
ServletHolder servletHolder = new ServletHolder(VmInspectionServlet.class);
servletHolder.setInitOrder(1);
handler.addServlet(servletHolder, "/*");
server.start();
Optional properties might be set to configure some aspects (either as spring-environment properties or servlet-init-parameters):
| Property | Default Value | Description |
|---|---|---|
| vminspect.path | /inspect/* | Only for spring-boot - Specifies the path to serve the VM inspection pages |
| vminspect.mbeans.readonly | false | Specifies if VmInspect is allowed to edit MBean values or invoke non-info operations |
| vminspect.mbeans.writeConfirmation | false | Specifies if a confirmation screen is displayed before edit MBean attributes or invoke MBean operations |
| vminspect.mbeans.accessControlFactory | none | Fully qualified class name of an implementation of the {@link MBeanAccessControlFactory} interface |
| vminspect.statistics.collection.frequencyMs | 60'000 | Number of milliseconds for the statistics collection timer |
| vminspect.statistics.storage.dir | none | Optional Path where to store the statistics files. If no storage directory is configured, the statistics will be kept in-memory and thus will be lost after a VM restart. |
- Attention: The latest inspect-version 2.0.0 supports spring-boot 3 and uses jakarta.servlet and no more javax.servlet (latest jakarta-servlet spec 6.0) - For javax.servlet support, use the 1.9 version or older
- Java 17 or higher (required by jakarta-servlet / spring-boot 3)
Maven users just need to add the following dependency:
<dependency>
<groupId>com.purej</groupId>
<artifactId>purej-vminspect</artifactId>
<version>2.0.0</version>
</dependency>
