Creating a Sample Distributable WAR File for JBoss EAP 8.1
JBoss EAP 8.1 supports HTTP session clustering, replicating a session across multiple JBoss EAP instances. This post won’t go deep into configuring the cluster itself, instead it focuses on the application side. Here’s a minimal WAR file you can deploy to an already-clustered JBoss EAP 8.1 environment to verify that session replication is working.
Below is my pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.edw</groupId>
<artifactId>jboss-eap-distributable</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<properties>
<maven.compiler.source>21</maven.compiler.source>
<maven.compiler.target>21</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<failOnMissingWebXml>false</failOnMissingWebXml>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.jboss.bom</groupId>
<artifactId>jboss-eap-ee</artifactId>
<version>8.1.0.GA-redhat-00001</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>jakarta.servlet</groupId>
<artifactId>jakarta.servlet-api</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.2</version>
</plugin>
</plugins>
</build>
</project>
And web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="https://jakarta.ee/xml/ns/jakartaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd"
version="6.0">
<display-name>JBoss EAP Distributable Hello World</display-name>
<distributable/>
</web-app>
The
This is my Java file which i use,
package com.edw;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
@WebServlet("/hello")
public class HelloWorldServlet extends HttpServlet {
private static final String COUNT_KEY = "count";
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
HttpSession session = req.getSession(true);
Integer count = (Integer) session.getAttribute(COUNT_KEY);
if (count == null) {
count = 0;
}
count++;
session.setAttribute(COUNT_KEY, count);
resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
out.println("<html><body>");
out.println("<h1>Hello World!</h1>");
out.println("<p>This application is cluster-aware (distributable).</p>");
out.println("<p>Session ID: " + session.getId() + "</p>");
out.println("<p>Session Count: " + count + "</p>");
out.println("<p>Server Time: " + new Date() + "</p>");
out.println("<p>Check your server logs to see session replication in action if running in a cluster.</p>");
out.println("</body></html>");
}
}
Once we have deployed this WAR to a cluster, say two EAP instances at 192.168.5.180 and 192.168.5.181, we can confirm the session is being replicated by reusing the same cookie jar across both nodes,
$ curl -kv http://192.168.5.180:8080/jboss-eap-distributable/hello -c cookies.txt -b cookies.txt $ curl -kv http://192.168.5.181:8080/jboss-eap-distributable/hello -c cookies.txt -b cookies.txt
If clustering is configured correctly, the second request should return the same session ID and an incremented session count, even though it hit a different node. If the session ID changes or the count resets to 1, that’s a sign session replication (or your load balancer’s sticky-session config) isn’t working as expected.
The whole source code for this project can be seen on the below repository,
https://github.com/edwin/jboss-eap-distributable
