Using proxy + server returns error = endless spam

[RohovDmytro]

If using proxy to send data to Segment through a custom URL, if the endpoint returns a valid error, the client keeps spamming the endpoint with no idea of pause between failed requests.

It makes sense to have a delay between attempts, which would be dynamic and go from 100 ms to couple of minutes.

This can be considered a feature request, but at the same time it's very fundamental and might lead to close-to-endless amount of requests, so I'd consider this as a bug.

Thanks.

[RohovDmytro]

In other words, having an exponential backoff is pretty crucial (to my taste).

[RohovDmytro]

Related discussion:

#448

[RohovDmytro]

After further investigation, I see there is some retry logic. It fails in this scenario:

const flushPolicies = [
  new FlushOnIdentifyOrAlias(),
  new BackgroundFlushPolicy(),
  new CountFlushPolicy(__DEV__ ? 1 : 10),
  new TimerFlushPolicy(__DEV__ ? 0 : 10000),
];

During dev I wait 0 ms before sending, which leads to spam-like behavior.

Also, as far as I understand now, the request will retry based on TimerFlushPolicy, which would be also suboptimal (though so much better than 0 timeout).

Then this Issue turns out to be a feature request to have an exponential backoff behavior to both have a good enough timer flush policy + avoid adding strain on the server.

[RohovDmytro]

Another suggestion would be to have such API:

new TimerFlushPolicy((info) => {
   return info.failedAttempts > 0 ? 60000 : 0;
});

Exposing some additional information to TimerFlushPolicy will enable the proposed feature.