In most systems, you're probably already doing it. Any ORM that has a level 1/2 cache built in (like Hibernate and EHCache/terracotta/etc or SQL caching in Rai

In most systems, you're probably already doing it. Any ORM that has a level 1/2 cache built in (like Hibernate and EHCache/terracotta/etc or SQL caching in Rails) is storing the data in more than one place. If the data is in the cache (or if the cache fails for whatever reason), you're in the same boat you are now. If you're just using redis for write-through caching/memoizatoin and there's some failure, you still have the answer in hand and can return it to the user, you just lose the benefit of the speedup from the cache.