Troubleshooting 5xx Responses

5xx status codes are generated by the web server associated with a customer origin configuration. By default, our edge servers will forward a 5xx response to requesterRefers to the user that requested content.s when a web server is unavailable and one of the following conditions are met:

• The web server has not been configured to reject connections when it is unavailable.
  • This type of setup may cause the web server to return an invalid response to our edge servers.
  • This type of setup will prevent a max-stale directive from taking effect.
• The requested content has not been cached on the POP closest to the requester.
• The requested content has been cached on the POP closest to the requester, but the asset's Cache Control response does not contain a max-stale directive.
• The requested content has been cached on the POP closest to the requester, but the asset's Cache Control response contains both max-stale and must-revalidate directives.

5xx responses are not typically related to our CDN service and must be resolved by a webmaster or system administrator.

Mitigation

Mitigate the effects of an unavailable web server by configuring it to:

• Reject connections when it is unavailable.
• Set an appropriate max-stale policy.
• Only set a must-revalidate directive as needed.

Learn more about Origin Shield.

Troubleshooting a Network Issue

A 5xx response may be a result of a network issue between the web server and the CDN.

Perform a traceroute from the web server experiencing issues to the primary CAN Gateway server as defined in the corresponding customer origin configuration.

Learn more.

A traceroute that reveals excessive latency is indicative of broader network issues

Status Codes

Additional information for specific 5xx status codes is provided below.

Status Code	Description
500 Internal Server	Indicates that the web server experienced an error that prevented it from serving the requested content.
503 Service Unavailable	Indicates that the web server is overloaded or down for maintenance.
504 Gateway Timeout	Indicates that a timely response was not received from the web server. Learn more.

Edgecast CDN