Help needed configuring retries in combination with timeouts

[williamcoates]

What would you like to discuss?

I am load testing our platform, and in a run I usually get a handful of dns lookup errors (since it opens socket but doesnt finish the lookup):

{
  "name":"TimeoutError",
  "code":"ETIMEDOUT",
  "timings":
     {
        "start":1612969156746,
        "socket":1612969156746,
        "error":1612969166750,
        "phases":{"wait":0,"total":10004}
    },
 "event":"request"
 }

I have this configuration:

    got.extend({
      dnsCache: cacheable,
      cache: httpCache,
      responseType: 'json',
      resolveBodyOnly: true,
      retry: {
        limit: 3,
        maxRetryAfter: 10000
      },
      timeout: {
        lookup: 1000,
        request: 10000
    })

I was trying to use got to retry after one second if there is a lookup failure, but when I add retry hooks I don't see any retries being attempted. So it seems like the lookup timeout is not causing a retry at all, but instead it is waiting to 10s and then not retrying because its already reached maxRetryAfter.

Is what I am trying to achieve not currently supported?

Checklist

• I have read the documentation.

[szmarczak]

It's hard to say what's going on without a reproducible code. You may want to have a look at https://github.com/sindresorhus/got#dnscache

[williamcoates]

Thanks for the fast response @szmarczak ! The dnsCache is just new CacheableLookup(fallbackDuration: 0). Unfortunately i still get dns failures which is odd. My guess is because it respects the TTL which is coming from the ELB of 60s (I cannot change that unfortunately).

I will investigate more...

[szmarczak]

What tool are you using to stress test your app? What about your DNS server - does it handle your load?

You can limit the retry time via a calculateDelay option.

[williamcoates]

We are using flood.io to stress test. The DNS server is AWS route 53, using private dns within the VPC, so together with the dns caching I would assume that wouldn't be the problem.

I configured just a lookup timeout now, and I can see that worked a couple of times, and the retry hook showed it retrying and then succeeding which is great.

But I still get three dns timeouts where the retry hook was not invoked a single time which is odd, and the timeout is about 2 minutes which is also peculiar.