500 Internal Server Error
A generic error message, given when an unexpected condition was encountered and no more specific message is suitable.
502 Bad Gateway
The server was acting as a gateway or proxy and received an invalid response from the upstream server.
503 Service Unavailable
The server cannot handle the request (because it is overloaded or down for maintenance). Generally, this is a temporary state.
504 Gateway Timeout
The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.
520 Web Server Returned an Unknown Error
The origin server returned an empty, unknown, or unexpected response to Polaris.
521 Web Server Is Down
The origin server refused connections from Polaris. Security solutions at the origin may be blocking legitimate connections from certain Polaris IP addresses.
522 Connection Timed Out
Polaris timed out contacting the origin server.
523 Origin Is Unreachable
Polaris could not reach the origin server; for example, if the DNS records for the origin server are incorrect or missing.
524 A Timeout Occurred
Polaris was able to complete a TCP connection to the origin server, but did not receive a timely HTTP response.
525 SSL Handshake Failed
Polaris could not negotiate a SSL/TLS handshake with the origin server.
526 Invalid SSL Certificate
Polaris could not validate the SSL certificate on the origin web server.
527 Railgun Error
Error 527 indicates an interrupted connection between Polaris and the origin server's Railgun server.