For anyone interested...
There is an old WebSphere table design for storing session and attribute details in Db2. However, I heard of locking problems with this, likely exacerbated by some dubious application configuration/design choices, but nonetheless...
So I thought I would try to improve on the design. My open source solution has just completed testing. It uses a new schema, and SQL modules for all data access.
https://github.com/easydataservices/db2-auth
The solution is engineered to minimise lock contention and avoid deadlocks, even under high load.
The solution should be usable in its current form. Longer term I was thinking of adding a caching tier and integrating with Spring SessionRepository. I also need to add some admin processes for housekeeping.
Jeremy Rickard