530 Site Frozen
HTTP response status code 530 is an unofficial server error that is specific to Cloudflare and Pantheon. In the case of Cloudflare, a second HTTP status code 1XXX error message will be included to provide a more accurate description of the problem. For Pantheon, HTTP status code 530 Site Frozen indicates that a site has been restricted due to inactivity.
Usage specific to Cloudflare
Cloudflare is a content delivery network that acts as a gateway between a user and a website server. When the 530 status code is received, it will be accompanied by a more detailed HTTP status code 1XXX error message. The errors vary in meaning and severity and are situation-dependent.
For example, Cloudflare HTTP status code 530 / Error 1016 Origin DNS Error is a case where HTTP status code 530 was returned, with the secondary HTTP status code 1016 Origin DNS Error further specified. In this very specific case, Cloudflare was unable to resolve the origin web server’s IP address due to a DNS error.
Usage specific to Pantheon
When a Pantheon Sandbox Site is inactive for a period of time, HTTP requests to it will be denied and the 530 Site Frozen status code is returned. The site owner can fix this problem by reactivating the site within the Pantheon User Dashboard.
Takeaway
The 530 HTTP status code generated by Cloudflare will provide an additional HTTP status code describing the error that occurred, whereas with Pantheon the HTTP status code indicates that HTTP requests are not being accepted because the site is frozen due to inactivity.