Error 520 from time to time

Hey there!

I’m having an issue with cloudflare. From time to time I get a 520 error while browsing the website and if I refresh the page it works.

I’m running LAMP with Laravel on a digitalocean droplet and I can’t find any logs on the server that tell me that there is an error.

Thank you.

Error 520: web server returns an unknown error

Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare.

Resolution

A quick workaround while further investigating 520 errors is to either grey cloud the DNS record in the Cloudflare DNS app or temporarily pause Cloudflare.

Contact your hosting provider or site administrator and request a review of your origin web server error logs for crashes and to check for these common causes:

  • Origin web server application crashes
  • Cloudflare IPs not allowed at your origin
  • Headers exceeding 16 KB (typically due to too many cookies)
  • An empty response from the origin web server that lacks an HTTP status code or response body
  • Missing response headers or origin web server not returning proper HTTP error responses

520 errors are prevalent with certain PHP applications that crash the origin web server.

If 520 errors continue after contacting your hosting provider or site administrator, provide the following information to Cloudflare Support:

With that being said what is your domain?

You are not alone: Intermittent Error 520, host says nothing in logs, Always Online off
The previous thread of over 150 posts discussing the same issue was closed as “fixed”: Sometimes a CF 520 error

Hi @pierre8,

Due to the number of 520s being reported in similar circumstances, we are escalating the issue to Cloudflare Support. The original incident should have been resolved and your issue may well be unrelated.

We recommend checking these troubleshooting tips, if you haven’t already.

If you have been through these thoroughly and are not seeing corresponding issues on your network/server and you have a ticket number with Cloudflare, please reply and post that #.

To enable efficient troubleshooting by support, please ensure you include the following on the ticket:

  • example URL(s) where you are seeing the error
  • Ray IDs from the 520 pages
  • output from a traceroute from any impacted user
  • output of example.com/cdn-cgi/trace - replace example.com with the affected domain.
  • Also include two HAR file(s) : one detailing your request with Cloudflare enabled on your website and the other with Cloudflare temporarily disabled - see How do I temporarily deactivate Cloudflare ?
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So as part of https://community.cloudflare.com/t/random-520-errors/ we fixed an issue with origins silently ending a keepalive connection that was causing very rare 520 errors.

Thus we recommend testing again - if you still see 520s - make sure you follow the guidance in our community tip here:

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