haproxy - how to share a session between two different tomcats

Question

Is it possible to share a session among 2 tomcats that runs the same web application and which is both balanced by haproxy? (haproxy is round robin based, and not using sticky-session)

by sharing i mean creating the session in one place (haproxy or tomcat) and be able to get it from the other tomcat.

(our goal is statless web application servers)..

Thanks!

Answer 1

It is possible. You can cluster your tomcat servers together.

Configure Tomcat to Share Sessions

The key to enable session sharing is to declare two XML elements: one in your application's web.xml (1) and the other in Tomcat's server.xml (2):

1. <distributable />
2. <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster" />

Important Note: Your session attributes must be serializable.

Sources:

• Krams - Clustering and Load Balancing... - very detailed step-by-step guide.
• Apache - Clustering HOW-TO - manual.