520 Errors when using CloudFlare Proxy

When creating a load-balanced infrastructure using OpenLiteSpeed as the webserver in some instances there is the possibility of receiving 520 Errors from CloudFlare.

Affects

Any load-balanced infrastructure that uses OpenLiteSpeed as the webserver and has CloudFlare Proxy set-up in front of the load-balancer.

Symptoms

  • Sporadic 520 Error that do not persist (upon refresh everything seems to work just fine)

  • No errors in the log that can be correlated/observed

Workaround

If you have configured the certificates correctly on the load-balanced infrastructure then temporarily suspending the CloudFlare protection for the affected site. This will ensure that the customer experience is not affected any longer.