Cache is King or Evil ?

Cache is King is an important read for understanding how cache plays role in a virtual directory. Without it, a virtual directory is simply an LDAP proxy/router. Future versions of Penrose will add a persistent cache and a synchronization service.

Cache is Evil is also an important read emphasizing the benefit of a having dynamic access functionality.

IMHO, “Virtualize if you can, synchronize if you must” is a good rule of thumb in designing multi-site and complex directory system.