Why are UK servers returning 522 errors?

Our website https://focusingonwildlife.com/news/ uses StatusCake, which checks pagespeed performance on hundreds of servers all over the world.

Starting 24 hours ago we noticed that there are many 522 error messages occurring only from UK servers in London, Manchester, Isle of Wight, etc. There are no 522 errors from other countries.

We checked with StatusCake and they informed us that the most common cause of error 522 is high server load and it’s usually produced by Cloudflare.

Please advise.

There doesn’t seem to be an outage in the U.K right now! Is this error occurring on your homepage or just that one page (the link you provided)?
Read below for more information on “Error 522: Connection timed out”

Error 522: connection timed out

Error 522 occurs when Cloudflare times out contacting the origin web server. Two different timeouts cause HTTP error 522 depending on when they occur between Cloudflare and the origin web server:

  1. Before a connection is established, the origin web server does not return a SYN+ACK to Cloudflare within 15 seconds of Cloudflare sending a SYN.
  2. After a connection is established, the origin web server doesn’t acknowledge (ACK) Cloudflare’s resource request within 90 seconds.

An HTTP 524 error occurs if the origin web server acknowledges ( ACK ) the resource request after the connection has been established, but does not send a timely response.

Resolution

Contact your hosting provider to check the following common causes at your origin web server:

  • (Most common cause) Cloudflare IP addresses are rate limited or blocked in .htaccess, iptables, or firewalls. Confirm your hosting provider allows Cloudflare IP addresses.
  • An overloaded or offline origin web server drops incoming requests.
  • Keepalives are disabled at the origin web server.
  • The origin IP address in your Cloudflare DNS app does not match the IP address currently provisioned to your origin web server by your hosting provider.
  • Packets were dropped at your origin web server.

If you are using Cloudflare Pages, verify that you have a custom domain set up and that your CNAME record is pointed to your custom Pages domain. Instructions on how to set up a custom Pages domain can be found here.

If none of the above leads to a resolution, request the following information from your hosting provider or site administrator before contacting Cloudflare support:

  • An MTR or traceroute from your origin web server to a Cloudflare IP address that most commonly connected to your origin web server before the issue occurred. Identify a connecting Cloudflare IP recorded in the origin web server logs.
  • Details from the hosting provider’s investigation such as pertinent logs or conversations with the hosting provider.

We have checked all of the 5 points in your resolution recommendation and also whitelisted all Cloudflare IP addresses. However 522 errors continue to be seen from UK servers (see attached screenshot).

Please advise how this issue can be resolved.

One of the failed pagespeed tests showed the traceroute details (see attached screenshot).

What exact steps have you taken to ensure the Cloudflare IPs arent being rate-limited or throttled? Because usually seeing something like this means that something is either rate-limiting or blocking them

We have carried our more tests as follows:

  1. Use of VPN’s - When browsing on a UK VPN the behavior is very erratic with long page load times. In addition images, which are cached by Cloudflare, do not open with a Simple Lightbox plugin (see attached screenshot). When browsing in all other countries the behavior is completely normal, and images can be displayed in the Simple Lightbox slideshow correctly.

  2. Cloudflare Development Mode - When the CDM is activated browsing on a UK VPN is a little slower than normal but the images can be displayed in the Simple Lightbox slideshow perfectly.

  3. UK Customers - Since this problem arose on 26 Oct 2021 at 09:15 CET several complaints have been received only from UK customers.

Does this serve to prove that the problem lies between Cloudflare and UK servers?

Please advise.

Attached the Cloudflare Error Analytics screenshot.

Please advise how to


resolve this issue.

Maintenance windows - We have read that during the following dates, Cloudflare will be performing maintenance on various data centers LHR (London) October: 25th - 27th and November: 2nd - 3rd.
There is a possibility of a slight increase in latency during these maintenance windows.

Can this be the cause of our 522 problems?

Our problems started on 26 October with many 522 errors on UK servers (see attached Cloudflare Error Analytics screenshot).

The 522 errors are occurring on all pages of our website but especially on pages containing several images. The 522 errors are not happening in any other country.

We have read that Cloudflare maintenance is taking place on various data centers LHR (London) October: 25 - 27 and November: 2 - 3.

Could this be the cause of our 522 errors?

Why am I not getting any advice how to resolve this issue?

Cloudflare was paused for 12 hours overnight, and there were no further 522’s on UK servers. The 522 problem is only occurring when Cloudflare is enabled.

Just as background information, we have been using Cloudflare for over 5 years and never had this 522 problem before. It only started on 26 October 2021 around the same time that Cloudflare servers in the UK began maintenance.

I guess that advisers on this Cloudflare Community do not have any authority to investigate problems on the Cloudflare network. If that is the case, what does one have to do to get support from Cloudflare technical support?

Can someone please advise me?

Thanks in advance.

That is correct. Most of us are just other customers.

What plan are you on? If you are on Free, then Community is the only support included in your plan.

If it’s a paid plan, to contact Cloudflare Customer Support, login & go to https://dash.cloudflare.com/?account=support and select get more help. If you cannot login, email [email protected] from the email address on your account. If you receive an automatic response that does not help resolve your issue, reply and indicate that you still require assistance. And, please share your ticket number here.

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