Internal Server Error, Bad Gateway, Service Unavailable and Gateway Timeout are the most common server error messages. Seeing any one among these errors generally indicates an issue with the URL's server.
Troubleshooting for Internal Server Error is mentioned
here.
Bad Gateway error, Service Unavailable and Gateway Timeout
Check if at the time when this error was occurring, other requests to your server will successful or not. You can check this by accessing the URL server's access logs and check the response code to the requests 30 minutes before and after Applications Manager reported the error. If other requests were failing as well, then check the URL's server for possible overloading or if it was under maintenance at the time.
Access the URL using the browser or cURL/Wget from the applications manager installed machine at the time the error is reported and check what response code is returned by using developer tools.
- If the response code returned in browser is 502, 503, 504, then check the URL's server for overload.
- If the response returned in browser is 200, Then check if the proxy is configured in applications manager. If the proxy is configured in applications manager and the proxy is not required for the URL, kindly add an entry for the URL's hostname in the "Do not use proxy for addresses beginning with" field. Similarly, If the proxy is not configured in applications manager and the URL requires proxy, Then configure proxy in applications manager.
In URL monitor, check "If monitor detects error, re-try immediately to verify error" option. This will allow Applications Manager to verify the server error before reporting the error thus avoiding false positives.