520, 522, 524 -- massive increase lately

Hello. I use cloudflare for several sites.

  • Some are Pro, some are free.
  • Some are Wordpress over apache (linux), some are ASP .Net over IIS (windows).
  • All use standard caching, all use FULL or FLEXIBLE ssl mode.

Regardless of the site, i have been seeing MAJOR issues with cloudflare in the last 2 weeks.
The sites are randomly spinning and pushing out timeout responses.

But when I disable cloudflare (grey cloud), the site runs just fine.
It seems to be picking and choosing which assets it wants to deliver to the client, causing major page spins in chrome.

I have contacted support through a ticket, and they are blaming the server.
Despite telling them the above specifically.

My question is…
Are any of you having the same experience? And if so, how do we escalate this to someone at Cloudflare who’s interested in digging to find answers instead of copy paste generic responses?

1 Like

Kindly, have you already checked here:

What are or is a domain name?

Do you use any other CDN with Cloudflare?
Do you use any CMS like WordPress?
Do you already have an SSL certificate installed at your origin/host for your Website(s)
(domains and sub-domains)?
Have you got CNAME or A records for your domains pointed to your origin/host IP address at Cloudflare dashboard?

Is Cloudflare allowed to connect to your origin/host?

1 Like

Thank you definitely appreciate the response. Yes, can confirm:

  • No Firewall block is occurring (one of the servers is godaddy, and CentOS on godaddy due to Virtuozzo has literally no iptables system running in kernel)
  • Again, turning off Cloudflare, site works fine.

  • Direct IP to server, no middleware or additional hops whatsoever
  • No CDN’s. I can see the 522/524 errors in chrome Network console and they are assets local to the server
  • We are using Wordpress, but we are also using Asp.net, and node js apps too. But if you can get a 522 error by manually copy/pasting the failed asset such as : https://mywebsite.com/assets/thing.css , and then turn Cloudflare off, and the same link works, then that’s cloudflare right?
  • I have SSL certs installed on the origin/host, using LetsEncrypt. But of course cloudflare provisions it’s own top-level global certificate to the browser. Again, i have tried both Flexible and Full modes. Flexible meaning cloudflare uses [http] instead of [https] when reaching out to origin.
  • DNS is all properly configured, no change in over 1.5 years of usage. Suddenly, last 2 weeks – bad.

We have nothing blocking cloudflare.
And specifically one of the servers literally has no firewall. It’s infuriating, but Godaddy refuses to allow iptables on virtuozza containers (aka their “dedicated hosting plan” ) … problem for another forum.
Point is – there is literally no firewall on the server, and the same problem happens.

Again though, and I must stress , it seems to be random!
It randomly picks which asset to 522/524, and randomly happens throughout the day.
I could get a 524 error right now, but 5 minutes from now you could try the same link and get a different result.

At this point I truly believe there is an issue with Cloudflare’s CDN or distribution system causing this.
Turning off cloudflare yields good results. Which is bad.

Does it mean anyone can connect?

Does ASP.NET support SNI for client connections?

Are the needed one and compatible ports with Cloudflare openned at the Origin/Host/Server and apps running on them (and not on the incompatible ones)?

Port 80 and Port 443, websites, so yes anyone can connect on ports with which a service is listening/responding.
Disabling cloudflare yields instantaneous responses on resources which with cloudflare enabled result int 520+ timeouts.

Asp.Net is separate from IIS, and IIS provisions SNI with a checkbox.
But these particular sites have their own certificate on a dedicated IP address, excluding the need for SNI.

But again, the problem is happening on two entirely separate servers, physically located in Ohio and Virginia, with separate IP addresses, and separate applications (linux apache wordpress, and iis windows asp.net). And they BOTH receive the 520+ timeouts randomly.

I fail to see how that could be a server configuration problem, since they are entirely separate entities running totally different stacks, resulting in the same CLOUDFLARE response code, which instantaneously is gone when disabling cloudflare?

Strange, but also interesting.

1 Like

My thoughts precisely!

I’m currently writing up a tiny browser js script to track response codes.
Will share asap if results are found.

Trying to find the right place to dig for answers. I am more than willing to accept it’s a server problem, but it denies all logic as far as I can tell :frowning:
I mean, if I’m the only one seeing this, then it must be me - somehow.


What is the domain name?

Is for clients of my company so I refrain to say, hoping with all my might and soul that I can replicate on this AWS Lightsail instance – shareable reference to problem

I am going through the same situation. In my case, it started this week, but precisely last Wednesday.

With Cloudflare active, the site is slow and randomly presents 5xx errors. Disabling Cloudflare the site works perfectly.

In contact with my host, they say that the problem is probably in Cloudflare.

And I don’t know what to do.

1 Like

Have you tried writing a ticket to Cloudflare support?


1 Like

Yes. I am waiting for an answer. In the meantime I have to keep Cloudflare deactivated for the site to work perfectly.

Mine began 2/20 and only resolve it to pause Cloudflare. All my sites are having this issue. None are on the same hosting account. So that rules a host issue. Seems something Cloudflare began on or around 2/20/21 is the cause.

Ran several hours without Cloudflare enabled and the site ran fine, loaded fast but soon as I re-enable Cloudflare it throughs this…

Error 520

Ray ID: 6294e12b7ebff021 • 2021-03-01 19:44:52 UTC

Web server is returning an unknown error

Since Wednesday February 24th, this has been happening to all of my sites (Error 520). Some are hosted on Godaddy, some are Hosted on A2, some on WPMUdev, some on Hostgator. Most have origin certificates from Cloudflare, but some are using flexible & self-signed, one or two are using paid-for SSL certs. Most are Wordpress, but some are Opencart, so there does not seem to be any one platform or plugin to blame either. The only common factor is Cloudflare.


Who is the hosting provider?

Have you tried checking with the steps on the below link?:

My website also started showing these errors on February 24th. And it continues today, but with less frequency.

I am keeping Cloudflare deactivated until I get an open Ticket response from them.

So this doesn’t get closed and lost BUMP!

Have you checked your web server log files and firewall?

This topic was automatically closed 5 days after the last reply. New replies are no longer allowed.