Django's builtin cached_db session allows me to use memcached to store session data, and write through to db for persistence.
While some applications use redis as their session store (instagram for one).
What is the pros and cons of these solutions?
p.s. I am not asking about the comparison between memcached and redis, which this question Memcached vs. Redis? already provides very good answers. I am asking about which one is better in case of a session system.