TTL and Expiry

Set a lifetime

TTL is time to live in seconds. Expired keys disappear automatically.

SET session:abc "data" EX 3600
TTL session:abc
EXPIRE cache:home 60

Persist forever again

Remove an expiry with PERSIST when you need the key to stay.

PERSIST session:abc
TTL session:abc

Millisecond precision

PEXPIRE/PTTL use milliseconds when you need finer control.

SET lock:1 "1" PX 500
PTTL lock:1

Design with expiry

Caches and sessions should almost always expire. Missing TTLs are a common cause of Redis memory growth.