hazelcast-session-classloading-issue

This project is based on hazelcast-docker-samples and demonstrates a class-loading issue with hazelcast-tomcat-sessionmanager in P2P Setup without sticky session.

The issue is present on Tomcat 7 and Tomcat 8.5.

We create a simple WAR as done in hazelcast-docker-samples but instead of putting a String in the session we use a StringHolder implements Serializable. Now we deploy this WAR under two targets (/example and /example2). Classloader for the StringHolder will be the first deployed application! The other one will throw an exception.

Requirements

You should have installed Docker and Apache Maven on your system.

Build

1. Clone repo - git clone https://github.com/helge79/hazelcast-session-classloading-issue.git

2. Create example war file - run mvn package

3. Navigate to directory tomcat7 (or tomcat85) and run run.sh shell file from terminal.

4. Look for the last deployed application (in my case it is mostly example.war - if not replace example by example2 below)

5. Open a browser and enter http://localhost:8080/example/hazelcast?key=foo&value=bar&action=Set+Attribute to set a attribute

6. Now get it via http://localhost:8080/example/hazelcast?key=foo&action=Get+Attribute => ClassCastException will be thrown:

   java.lang.ClassCastException: com.hazelcast.HazelcastSessionReplication.StringHolder cannot be cast to com.hazelcast.HazelcastSessionReplication.StringHolder