I want to ask: when I started pointing ip hosting to cloudflare, how long do the cloudflare system record?
I have proceeded to point ip hosting to cloudflare and point the domain name to the nameservers of cloudflare at 10am (GMT +7) today, but now is 6pm (GMT +7) my web still has an Error 502 Bad gateway!
The 502/504 errors are caused by a problem connecting to an upstream server - meaning your server is trying to initiate a process and this fails to work as expected or times out. In most cases of 502 / 504 errors, back-end servers are not communicating correctly. When this happens, you will see color page with Cloudflare branding and the Error 502 Bad Gateway or Error 504 Gateway Timeout. Review this Community Tip for fixing 502 or 504 gateway errors.