Error 429: Insufficient tokens (DefaultGroupUSER-100s) What defines a user?

Question

tl/dr do 100 devices all using the same Client ID count as 100 users, with their own limits, or one user sharing limits?

I have a webpage which reads and writes to a Google Sheet.

Because the webpage needs to know if a cell has changed, it polls the server once every 1000ms:

var pollProcId = window.setInterval(pollForInput, 1000);

where pollForInput does a single:

gapi.client.sheets.spreadsheets.values.get(request).then(callback);

When I tried to use this app with a class of 100 students I got many 429 error codes (more than I got successful reads) in response to google.apps.sheets.v4.SpreadsheetsService.GetValues requests:

Many of my users never got as far as seeing even the first request come back.

As far as I can make out, these are AnalyticsDefaultGroupUSER-100s errors which, according to the error responses page:

Indicates that the requests per 100 seconds per user per project quota has been exhausted.

But with my app only requesting once per 1000 milliseconds, I wouldn't expect to see this many 429s as I have a limit of 100 requests per 100 seconds (1 per second) so only users whose application didn't complete in 100 seconds should have received a 429.

I know I should implement Exponential Backoff (which I'll do, I promise) but I'm worried I'm misunderstanding what a "user" in this context is.

Each user is using their own device (so presumably has a different IP address) but they are all using my "Client ID".

Does this scenario count as many users making one request per second, or a single user making a hundred requests per second?

Answer 1

Well, the user in the per user quota means that a single user making a request. So let's take the Sheets API, it has a quota of 100 for the Read requests per 100 seconds per user. So meaning only a single user can make a request per second. Note that Read request has a same set of quota as the Write request. But these two sets of quotas have their own set of quota and didn't share the same limit quota.

If you want a higher quota than the default, then you can apply for a higher quota by using this form or by visiting your developer console, then click the pencil icon in the quota that you want to increase.

I also suggest you to do the Exponential Backoff as soon as possible, because it can help you to avoid getting this kind of error.

Hope it helps you.