encountering invalidation issues, please report a bug and see the
:ref:`manual-invalidation` section for possible workarounds.
+Johnny supports multiple databases in a variety of configurations. If using
+Johnny to cache results from a slave database, one should use the
+``DATABASES .. JOHNNY_CACHE_KEY`` setting (see below) to ensure that slave
+databases use the same database key as the master database.
+Please note that, in a master/slave database configuration, all of the typical
+problems still exist. For example, if you update a table and then initiate a
+read on the slave before the change has had time to propagate, stale data may
+be returned and cached in Johnny. As such, be certain that read queries
+prone to this issue are executed on a database that is guaranteed to be up to