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.