Fastify rate limit not working with pm2 and redis

Question

I am using pm2 (in cluster mode) and redis. I want route level rate limit configuration. The docs mention that redis property must be set if we have fastify-rate-limit on more than one server which I'm assuming applies to me as I'm using pm2.

Here's my fastify configuration:

const createClient =  require('redis').createClient;

fastify.register(require('@fastify/rate-limit'), {
  global : false,
  redis: createClient("redis://redis_url")
})

An example route on which I'm testing the rate limit.

fastify.get('/hello',{
  config: {
    rateLimit: {
      max: 1,
      timeWindow:  '1 minute'
    }
  }
}, async (req, reply) => {
  reply.send("world")
})

However, it isn't working. I am able to hit the /hello route more than once per minute.

How may I fix this?

Answer 1

Here is the same issue

You need to await the plugin to make it works.

await fastify.register(require('@fastify/rate-limit'), {
  global : false,
  redis: createClient("redis://redis_url")
})

fastify.get('/hello', { ... })

This is needed due onRoute hook and it is part of the fastify@4 breaking changes: https://www.fastify.io/docs/latest/Guides/Migration-Guide-V4/#synchronous-route-definitions-2954