Improving Key Expiration in Redis

After a lot of time spent debugging and testing we were able to reduce Redis’s memory use in some of our clusters by up to 25% with changes to key expiration. Unfortunately, the resolution at the time was to increase the size of the cluster and more hardware so keys would be spread around more and there would be more memory available. This idea mostly worked, we were able to see memory use was lower, latency wasn’t affected, and a metric tracking sample size showed it was increasing and decreasing over time.

Source: blog.twitter.com