Given that Ignite has replaced ehcache the sitestats external db config needs to be updated accordingly.
If the external db should be using query cache or 2nd level cache then there will need to be some additional configuration on the part of Ignite to create a separate l2 region for the external db. Another issue should be created for this purpose.
In this Jira were simply disabling the query cache so users who wish to use the external db without anything additional can. (Note 2nd level cache was not enabled for the external db)