If a request sent to a web server through an http proxy fails, an error status code is received. A 5xx error occurs when the server successfully receives a request but cannot process it or encounters a problem during processing.
If you want to continue using an http proxy, you must first understand the meaning of various error status codes. Here is an introduction to the types and meanings of http proxy server error codes.
500–Internal Server
The error code “500–Internal Server” is received when the server encounters an unexpected situation, preventing it from responding to the request.
501–Not Implemented
When the server cannot provide the requested resource because the method used in the request is unsupported or unrecognized, a “501–Not Implemented” error is received.
502–Bad Gateway
This error often occurs during data collection when the server acts as a gateway or proxy and receives an invalid response from another server.
When the super proxy rejects the Internet connection or the request sent, it detects that the IP is unavailable for the selected settings because the robot indicates a 502 code.
503–Services Unavailable
The “503–Services Unavailable” code is received when the server receives a request while it is overloaded with other requests, or it is under planned downtime/maintenance. In this case, check the status of the requested server if possible.
504–Gateway Timeout
A “504–Gateway Timeout” is received when a server (a) is acting as an external gateway or proxy and does not receive a timely response from the next server (b) further up in the chain of requests that it is trying to access to complete the request.
505–HTTP Version Not Supported
A “505–HTTP Version Not Supported” code is received when the server does not support the HTTP protocol version and is used in the request message.
507–Insufficient Space
“507–Insufficient Storage” means that the server has insufficient disk space and can no longer accommodate the request.
510–Extensions are Missing
The server cannot process the request because an unsupported extension was requested, and then receives the code “510–Not Extended”.