We have a system that 302 redirects users to different other websites based on several criteria and we have big-query analytics & grafana that help us visualize the business.

The system is getting about 35k requests a day, and we noticed that there's 2.5-3% difference between our providers and what we actually get. So every 100 requests the provider is logging, we only get 97-98. We wanted to verify where the issue is, so we redirected all the traffic to ourselves before passing it on, and again we see another 2.5-3% of requests. This is not related to unprocessed analytics events as we're looking at data from 24 hours ago.

It seems like some of the redirects get dropped for some reason. We're 100% sure it's not inside the system itself. We added logs, metrics and what not, and we're sure that every request we get is properly logged and analyzed. Running stress tests from a single computer of up to 100 rps all accepted and logged

Is it common that 302 redirects get dropped so much?

Relevant technologies we're using:

1. Cloud Run with custom domain (we increased min instances to prevent possibility of dropped due to scaling issue)
2. Cloudflare - DNS only to google servers
3. Express - No cache header

Thought I'm considering but found no evidence of:

1. Some ISPs/Google might very briefly cache requests
2. Some browser issues, dropping some redirects or sharing some 302 redirects - but very unlikely
3. There's still some problem with our app

Any thought/help will be very much appreciated.