Random 502 errors for last 3 days (caused by illegal request header injected by CF reverse proxy)


They probably didn’t see any significant spike in error rates. Because 1. there’s only small amount of server being deployed, 2. only impacts IIS + Asp.net core through ARR, which only be small portion along with all other web hosting server types.

In term of owner of those sites with error, probably most of them didn’t notice this neither, as you will not see error log in hosting server. Unless there’re reports from user. But 502 is a very tricky error, as Cloudflare always blame it to the hosting server. And truth is in most of case, it was the hosting servers. But I agree with you, they need put other measure to monitor the canary releases. If you cannot verify it properly, it’s not a “canary” release.

Only thing I’m not quite happy here is, it wasted me entire day to investigate the issue, especially during a very busy period. And after I found the reason, they ignores me. @akrivit, check how long took your support team to response to my request, even after I inlcuded the detail of reason. If I didn’t start twitting around, the ticket will be kept on ignoring, or just closed as regular 502 timeout error.