Recently we faced a session expiration problem while accessing Web Applications running on SAP J2EE Engine in a load balanced environment with multiple physical servers to achieve High Availability(HA).
To understand and fix the problem we have to understand the structure of SAP J2EE Engine Cookie in the Load Balanced Environment. Since this is a very common scenario, I thought lets share this with everyone.
When a user accesses a Web Application (say WebDynpro), the SAP J2EE Engine returns a cookie for performing session tracking and load balancing. You can check this cookie using the keyword
in the address field in the browser window where the application is being accessed. If you are accessing Web Application directly (without SAP Enterprise Portal) and have a load balancer in your environment, the output will be similar to image below.
If you are accessing Web Application using SAP Enterprise Portal and have a load balancer in your environment, you will see an output similar to image below.
This cookie generated by SAP J2EE Engine has two main parts:\j2ee\configtool
After understanding the above we were able to solve the session expiration problem with Cisco Load Balancer which I will explain in my next Blog.