Memcached 30 days problem
Memcached's maximum key expiration time is 30 days. But, what would happen if You set more?
As a developer I would say that memcached should either throw an exception, or at least put "UNABLE TO STORE" in the log. Instead of that memcached simply throws away Your entry, and log "STORED", that's why:
An expiration time, in seconds. Can be up to 30 days. After 30 days, is treated as a unix timestamp of an exact date.
There is a tip that can help You out if a really long lifetime is needed, just put "0" as a lifetime - it means forever.