Distributed HTTP session state server for tomcat

Question

One of our Spring MVC web application is deployed on multiple web servers with tomcat 7 and LB is at front to balance and distribute the requests to appropriate tomcat server.

Problem with this web farming is each tomcat server is able to store and retrieve its own HTTP session, but LB can send requests to any one of web server. So if a user is served for login page through tomcatServer1 then it's HTTP session will be created on it's respected server and it may happen that for second request of dashboard page LB sends it to tomcatServer2 where HTTP session is not available, resulting user is again redirected to login page.

To overcome this,

1. we are using "Sticky Session" property on LB, so that if a user (HTTP session + user's public IP) is first time served from tomcatServer1 then it will get bound to that server. Setting "Sticky Session" is not helpful as it's not utilizing all servers equally.
2. Another way is, develop our own session state server and deploy on a server then all server should communicate to that server for storing and retrieving session object/data.
3. Providing custom SessionManager to Servlet Container.

About #2, If in case we able to develop state server then also I have to modify the code to related to HttpSession.setAttribute() and HttpSession.getAttribute() . So question is, is it possible to override implementation of HttpSession for methods setAttribute & getAttribute? Also About #3, I don't know whether this solution will provide distributed state session server?

Answer 1

I developed session state server for tomcat using python.

Due to this I don't need to change the code already written for creating/accessing and destroying session. Also as there is separate server/service which is handling and storing session so not master cluster is needed.