Error 521 invoking a worker
Hello,
Today between 6:30 and 7:30 UTC, I received ~750 HTTP 521 errors trying to invoke my worker, which account for ~8% of error rate. I did not find anything on https://www.cloudflarestatus.com/, and I'm wondering if I got rate limited or if I can do something to avoid this problem in the future. I'm on a paid plan.
I'm open to any ideas to investigate this, thank you 🙏
6 Replies
521 typically indicates an origin timeout. Anything on your origin side?
Or what is this Worker doing? Is it fetching an origin (even if not owned by you)?
The worker is used for uptime monitoring checks, but as suggested on the graph the 750 workers did not get invoked, so it seems to be between my backend and the worker invocation. And from my understanding in that flow the origin behind Cloudflare is the worker endpoint ?
I'm fine with some error rate, It's just that I migrated my script from Lambda to Cloudflare a few days ago so I'm heavily monitoring and would like to know if this is something that could happens a lot or if it's extraordinary, or even a fail on my side 🤔
oh this is worker invocations
Will require some deeper digging than we can really provide on Discord, have you got a ticket?
No I can't create a support ticket with my free account, I'm only paying for workers as it's the only thing I need for the moment
Thank you for your help Walshy, I'm going on holidays for a week so I won't be able to follow up on this, I'll see if this happens again when I get back and contact support then
We also got the same 521/523 error in the worker fetch.
I'm back from holidays, I invoked ~2M workers in the past week and still got a few 521 / 500 errors, but it stays well under 1% which is acceptable. I will update my code to bulk my requests and add a retry mechanism on my backend to improve reliability 👌