The PHP manual for Memcache doesn't have any explanation for the memcache.session_redundancy option. The comment on that page (which is 4 years old) says it sets the number of copies of a session object.
In another old question on memcache this answer says the the value should be N + 1, N being the no. of servers in the pool.
I'm setting up three LAMP servers to share their sessions using php5-memcache. I have left memcache.session_redundancy to its default 2 and it works fine.
What exactly is memcache.session_redundancy directive? Should I change it to 4 (3 servers + 1)?
