redis-rate-limiter

rate limiter implemented with redis lua script

NOTE: redis will lock whole server while executing a script, so better use a standalone redis for rate-limiter

Features:

• Check and set (CAS) is implemented with lua script. This is probably the only way to support CAS for single redis client. (See https://redis.io/commands/eval)
• Support punishment. If a limiter is reached and punishment is set, same event will be banned for a specified period.

Flow:

• For every limiter, no more than limit events can pass.
• If only the event passed all limiters, the event can pass.
• If the event passed all limiters and the counter equals limit and there is any punishment, ban this event with maximum of all punishments of limiters.

Limiter configuration example:

[
  { period: 60, limit: 3, punishment: 60 * 15 },
  { period: 60 * 60, limit: 9 },
]

see examples for more details