Translate API User Rate Limit Exceeded [403] without reason

Question

I use google translate API with C# code via "Google.Apis.Translate.v2" version 1.9.2.410 with paid service.

Code is some like:

var GoogleService = new Google.Apis.Translate.v2.TranslateService(
 new BaseClientService.Initializer
{
    ApiKey = Context.ConfigData.GoogleApiKey,
    ApplicationName = "Translator"
});
...

  var rqr = GoogleService.Translations.List(item, 'de');
  rqr.Source = "cs";

  var result = await rqr.ExecuteAsync();

This code take Exception:

User Rate Limit Exceeded [403] Errors [ Message[User Rate Limit Exceeded] Location[ - ] Reason[userRateLimitExceeded] Domain[usageLimits] ]

Before that, it never was. My limit it's: Total quota 50 000 000 characters/day Remaining
49 344 849 characters/day 98,69 % of total Per-user limit
100 requests/second/user

The number of requests is certainly less than 100 request per second Please what's wrong?

cjlallana cjlallana · Accepted Answer · 2015-11-27T11:36:04

There is an existing undocumented quota for Translate API. This quota limits the number of characters per 100 seconds per user to 10,000 (aka 10,000 chars/100seconds/user).

This means that, even if you’re splitting large texts into different requests, you won’t be able to bypass 10,000 characters within a 100-seconds interval.

Brief examples:

If you bypass 10k characters within the first 5 seconds, you will need to wait 95 seconds to continue analyzing chars.
If you hit this quota after 50 seconds, you will need to wait another 50.
If you hit it on the second 99th, you will need to wait 1 second to continue the work.

What I would recommend is to always catch exceptions, and retry a number of times doing an exponential backoff. The idea is that if the server is down temporarily due to hitting the 100-seconds interval quota, it is not overwhelmed with requests hitting at the same time until it comes back up (and therefore returning 403 errors continuously). You can see a brief explanation of this practice here (the sample is focused on Drive API, but the same concepts apply to every cloud-based service).

Alternatively, you could catch exceptions, and whenever you get a 403 error, apply a delay of 100 seconds and retry again. This won't be the most time-efficient solution, as the 100-seconds intervals are continuous (not started when the quota is reached), but it will assure that you don’t hit the limit twice with the same request.

Translate API User Rate Limit Exceeded [403] without reason

1 Answers