527 Railgun Listener to Origin
HTTP response status code 527 Railgun Listener to Origin is an unofficial server error that is specific to Cloudflare. This HTTP status code occurs when there is an error between Cloudflare and the origin’s Railgun server.
Usage
Cloudflare is a content delivery network that acts as a gateway between a user and a website server, and Railgun is a network optimizer that boosts the speed of the HTTP Connection between Cloudflare and the origin server using techniques such as HTTP compression. When the 527 Railgun Listener to Origin status code is received, it indicates an error between Cloudflare and the origin’s Railgun listener (rg-listener). For example, the HTTP Connection may have been interrupted or a timeout occurred.
Takeaway
The 527 Railgun Listener to Origin status code is a Cloudflare-specific server error that is generated because of an error that has occurred between Cloudflare and the origin’s Railgun server.