527 Railgun Error
527
Railgun Error
Example HTTP Response
HTTP Response
HTTP/1.1 527 Railgun Listener Error
Server: cloudflare
Content-Type: text/html
<html><body>Error 527: Railgun Listener error</body></html>Common Causes
- Railgun listener not responding
- Railgun service crashed or stopped on origin
- Firewall blocking Railgun connection (port 2408)
- Railgun listener timeout
- Railgun software misconfigured
- Origin server resources exhausted affecting Railgun
- Network issues between Cloudflare and Railgun listener
Technical Details
What does this mean?
The express train broke down! Cloudflare tried to use the super-fast Railgun connection to your origin but the rail line is having issues. Time to call maintenance!
Technical Definition
The request failed after Cloudflare established a connection to the origin Railgun server. Railgun is Cloudflare's deprecated WAN optimization technology.
Code Snippets
Ready-to-use code for returning this HTTP status in your application:
Node.js
// Express.js
app.get('/example', (req, res) => {
res.status(527).json({
error: 'Railgun Error',
message: 'Your error message here'
});
});
// Native HTTP
const http = require('http');
http.createServer((req, res) => {
res.writeHead(527, { 'Content-Type': 'application/json' });
res.end(JSON.stringify({
error: 'Railgun Error',
message: 'Your error message here'
}));
}).listen(3000);Related Status Codes
527 Railgun Error FAQ
What causes a 527 Railgun Error error?
Railgun listener not responding. Railgun service crashed or stopped on origin. Firewall blocking Railgun connection (port 2408). Railgun listener timeout. Railgun software misconfigured. Origin server resources exhausted affecting Railgun. Network issues between Cloudflare and Railgun listener.