Erreur 502 intempestives surtout en backend

What is the name of the domain?

What is the error number?

502

What is the error message?

Web server is returning an unknow error

What is the issue you’re encountering

Too many untimely 520 type errors, especially in the Backend. After a certain number of screen refreshes, the error disappears.

What steps have you taken to resolve the issue?

check logs and save HAR files

What feature, service or problem is this related to?

I don’t know

What are the steps to reproduce the issue?

move around the site

Screenshot of the error

Hi there,

Checking our own logs, these are the errors I get in each 520:

45.6%:

“message”: " context: while reading h2 header cause: stream closed because of a broken pipe",

29.6%:

“message”: " context: while reading h2 header cause: connection reset",

The remaining ones are:

“message”: " context: while reading h2 header cause: timed out",
“message”: " context: while read h2 response body cause: connection reset",
“message”: " context: while read h2 response body cause: timed out",

This seems to heavily imply something wrong with either the headers or the way the origin is interpreting and responding to HTTP/2 requests.

I see this only started happening recently, so the reason here might be origin incompatibility with Multiplexing since Cloudflare started rolling it out:

Connection multiplexing is currently being rolled out. It has been enabled by default on Free, Pro and Business zones. Enterprise zones will be enabled at a later date.

Having said this, my advice is that you check if there’s an option at your origin/hosting provider to enable multiplexing, if not, you can probably overcome the issue by going to Speed > Optimization > Protocol Optimization in your dashboard and disable HTTP/2 to Origin.
If this solves your issue, please contact your hosting provider and request they enable multiplexing for you, and you can then re-enable HTTP/2 to Origin again.

Take care.

Hello,
I made the suggested fix by disabling HTTP/2 to origin.
I am now encountering 520 errors as well as site crashes, especially in the backend.
“An error occurred while retrieving JSON data: HTTP status code 520
I am hosted by OVH.
Regards


I contacted OVH as you suggested and am awaiting their response.

I also randomly receive the message in the backend: “Error
An error occurred while retrieving JSON data: HTTP status code 524.”

Hi there,

Please try following these steps:

Take care.

Thank you,
Sorry, I’m just an advanced user. I have read the documentation but I don’t understand how to code the Joomla exclusion.
Can you please explain how can I code the Joomla exclusion.
Regards

Hi there,

Is your administrative panel under /administrator? If so, please try this:

Don’t forget to also allow Cloudflare IP addresses otherwise, it might result in the 524 you’re getting:

Take care.

I keep getting 520 errors.

I tried the following in .htaccess, but it blocked the site.
Can you help me?

Require ip 103.21.244.0/22 Require ip 103.22.200.0/22 Require ip 103.31.4.0/22 Require ip 104.16.0.0/13 Require ip 104.24.0.0/14 Require ip 108.162.192.0/18 Require ip 131.0.72.0/22 Require ip 141.101.64.0/18 Require ip 162.158.0.0/15 Require ip 172.64.0.0/13 Require ip 173.245.48.0/20 Require ip 188.114.96.0/20 Require ip 190.93.240.0/20 Require ip 197.234.240.0/22 Require ip 198.41.128.0/17

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