What kind of network error is Chrome encountering when 'Status = (failed)' and 'Type = undefined'

Question

Sometimes I randomly see network requests from Chrome failing with Status = \'(failed)\' (status code 0 from the request object in JavaScript) and the response type as \'und

Answer 1

We had exactly this issue with an application reaching an API we control. It took a while for me to realize that slower clients were not seeing the issue, whereas faster clients (and pages with more requests) were.

It turned out that our HA Proxy was rate limiting requests on our frontend. Once we raised the limit from the value of 20 we had set up to something around 100, we no longer had the issue.

So it's possible you're getting blocked by something along the request pathway, potentially a proxy or load balancer or even a firewall.