11.1 Adding functionality without writing C

Prior to Redis 2.6 (and the unsupported scripting branch of Redis 2.4), if we wanted
higher-level functionality that didn’t already exist in Redis, we’d either have to write
client-side code (like we have through the last 10 chapters), or we’d have to edit the C
source code of Redis itself. Though editing Redis’s source code isn’t too difficult, supporting
such code in a business environment, or trying to convince management that
running our own version of the Redis server is a good idea, could be challenging.

In this section, we’ll introduce methods by which we can execute Lua inside the
Redis server. By scripting Redis with Lua, we can avoid some common pitfalls that slow
down development or reduce performance.

The first step in executing Lua code in Redis is loading the code into Redis.