Scaling Out

Spreading load across machines, and the statelessness that makes it possible.

5 concepts · 185 minutes

• CDNs & the EdgeMove the bytes closer to the user — the highest-leverage latency fix available.
• HTTP CachingCache-Control, ETags, and revalidation — the cheapest performance win that exists.
• Caching with RedisAn in-memory store used as cache, session bag, lock, counter, and queue.
• Load BalancingSpreading traffic across machines, and what breaks the moment there's more than one.
• Scaling Out & StatelessnessWhy your server must not remember anything locally if you want a second one.