Redis 4.x Cookbook

How to do it...

To show how to set expiration on keys, we store the IDs of five restaurants that are closest to the user's current location in a Redis list. As the user's location may change frequently, we should set a timeout on this Redis list. After the timeout has expired, we will fetch the restaurant list again using the current location:

1. Create a Redis list of restaurant IDs at key closest_restaurant_ids:

127.0.0.1:6379> LPUSH "closest_restaurant_ids"109 200 233 543 222
(integer) 5

2. Set the timeout on the key to 300 seconds by using the EXPIRE command:

127.0.0.1:6379> EXPIRE "closest_restaurant_ids" 300 
(integer) 1

3. We can use the TTL command to check the remaining time before the key expires:

127.0.0.1:6379> TTL "closest_restaurant_ids" ...