Customers Reporting 522 timeout errors occurring randomly

Website, Application, Performance
1

What is the name of the domain?

https://shorturl.at/Pes523

What is the error number?

522

What is the error message?

522: Connection Timed Out to Origin

What is the issue you’re encountering

Some of our clients are getting a 522 error intermittently, occurring in about 5% of user requests.

What steps have you taken to resolve the issue?

  • Checked all solutions listed in Community Tip - Fixing Error 522: Connection timed out.
  • Also reviewed the solutions listed in cloudflare support for Error 522.
  • Confirmed no server overloading - the application server has enough capacity; CPU, memory, and process limits are all normal.
  • Ensured no Cloudflare IP is blocked by the firewall. It is updated with the latest IPs
  • Checked MTR reports from client IP to the URL, and found no issues.

What are the steps to reproduce the issue?

We cannot reproduce the issue from our side as it is occurring randomly, but the Cloudflare analytics show that the issue exists.

2

There is an increase in connections in the SYN_RECV state from the TCP connection analysis on the VM, which shows a similar trend to the Cloudflare 522 error analysis.

So assuming 2 possible causes,

  • The SYN_ACK is not reaching back to cloudflare.
  • Cloudflare final ACK is not reaching to the VM…

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image2149×999 290 KB

3

Cloudflare analysis data for same period

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image1712×1143 97.4 KB

4

Closing the issue as Cloudflare support team responded to the support ticket. It was a technical issue on Cloudflare’s side due to a problematic server. They have isolated and resolved the issue.

5

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