No way to determine if underlying connection has been killed

[phawxby]

In the event that client.quit(); is called I would expected client.status to update to something like disconnecting or closing and then to close once complete. That does not happen.

    console.log(this._redisClient?.status);
    await this._redisClient?.quit();
    console.log(this._redisClient?.status);
    await this._redisClient?.quit();
    console.log(this._redisClient?.status);
    
    OUTPUT
    
ready
ready
[ioredis] Unhandled error event: Error: write EPIPE
    at afterWriteDispatched (node:internal/stream_base_commons:164:15)
    at writeGeneric (node:internal/stream_base_commons:155:3)
    

The same applies when calling await this._redisClient?.quit(); too.

Incidentally it would be good to get some tsdocs on the statuses so it's obvious what they mean, for example what's the difference between end and close
https://github.com/luin/ioredis/blob/main/lib/Redis.ts#L37-L44

[phawxby]

After some investigation it seems the issue is that there is no intermediate state before end. Like reconnecting or connecting there should be an ending status which indicates that the connection is in the process of being closed, up until that point it responds as ready even though it's being killed in an async fashion.

Perhaps disconnect should be awaitable until disconnection has occurred.

[martinffx]

@luin @phawxby this seems related to: #1362

We've run into this in our Jest tests complaining about open handlers... would be nice to get a fix for this?

[martinffx]

I did this to cleanly close the client with Fastify.

const registerRedis = (server: FastifyInstance) => {
  const redisClient = new Redis(process.env.REDIS_URL || '', { disconnectTimeout: 100 })
  server.decorate('redis', redisClient)

  server.addHook('onClose', async (instance) => {
    await instance.redis.quit()
    await new Promise((resolve) => {
      instance.redis.disconnect()
      setTimeout(() => { resolve(null) }, 100)
    })
  })
}