Wonder why Cloudflare throws an error on my server which is up? I can verify the server is up by visiting the ip in my browser.
I checked system log, apache log, no error found. Btw, I just set the domain on a static site.. I can't figure out how to fix it. Googled and found no solution
A 524 error states that CloudFlare was able to make a TCP connection to the origin, but the origin did not reply with a HTTP response before the connection timed out. This means that CloudFlare is able to make a network connection to the origin server, but the origin server took too long to respond to the request.
https://support.cloudflare.com/hc/en-us/articles/200171926-Error-524-A-timeout-occurred
If your process take more than 100 seconds (1.67 Minutes) then CloudFlare throws an error, This link resolves in PHP.
In PHP app this could be that session don't return data - It hang on because of cookies. Clear application data to create new session and try again.
Official for default and free is 100 seconds before Cloudflare send this header. For enterprise there is 524 to max 600 seconds option (not default)