http://simonwillison.net/2010-02-14T17:17:29+00:00Simon Willison2010-02-14T17:17:29+00:002010-02-14T17:17:29+00:00https://simonwillison.net/2010/Feb/14/redis/#atom-tag

<p><strong><a href="http://www.lukemelia.com/blog/archives/2010/01/17/redis-in-practice-whos-online/">Redis in Practice: Who&#x27;s Online?</a></strong></p> Using Redis to implement a “which of your friends are online now” feature, by maintaining a set of active user IDs for every minute, then intersecting the past five minutes of user IDs with a set containing the IDs of your friends. <p>Tags: <a href="https://simonwillison.net/tags/friends">friends</a>, <a href="https://simonwillison.net/tags/luke-melia">luke-melia</a>, <a href="https://simonwillison.net/tags/online">online</a>, <a href="https://simonwillison.net/tags/redis">redis</a>, <a href="https://simonwillison.net/tags/social">social</a></p>