JFR Servlet

A servlet filter that generates JFR events.

<dependency>
  <groupId>com.github.marschall</groupId>
  <artifactId>jfr-servlet</artifactId>
  <version>2.0.0</version>
</dependency>

This project requires Java 11.

Versions 1.x are for the javax.servlet namespace, versions 2.x are for the jakarta.servlet namespace.

Usage

If your web application is not metadata-complete then you only need to add the dependency.

If your web application is metadata-complete then you manually need to add the filter com.github.marschall.jfr.servlet.JfrFilter and map it.

<filter>
  <filter-name>JfrFilter</filter-name>
  <filter-class>com.github.marschall.jfr.servlet.JfrFilter</filter-class>
  <async-supported>true</async-supported>
</filter>

<filter-mapping>
  <filter-name>JfrFilter</filter-name>
  <url-pattern>/*</url-pattern>
  <dispatcher>REQUEST</dispatcher>
  <dispatcher>FORWARD</dispatcher>
  <dispatcher>INCLUDE</dispatcher>
  <dispatcher>ERROR</dispatcher>
  <dispatcher>ASYNC</dispatcher>
</filter-mapping>

Correlating Dispatches

A single request may traverse the servlet chain multiple times, either because of a server side redirect or because of asynchronous processing. We generate a unique exchangeId for every request so that multiple dispatches of the same request can be correlated.