Oracle Coherence is a in-memory data grid product, which is also being used commonly for Session Replication across cluster of application server nodes. It supports wide variety of application servers like WebLogic, WebSphere, Tomcat, JBoss, etc. Coherence*Web is Session Management module (built on top of Coherence) used for managing session information in clustered environment.
I would recommend following best practices w.r.t. Coherence*Web & Coherence usage particularly for Session Management (it can also be applied in other Coherence scenarios):

http://ankurkumar78.blogspot.com/2011/08/oracle-coherence-best-practices-in.html