Error 503 Backend Unavailable, Connection Timeout
A 503 Service Indisponible Error is an HTTP response status code that means that the server is temporarily unable to handle the request. This could be due to the overloading of the computer or uploading for maintenance.
As mentioned above, 503 Service Unavailable Error means that the server (usually the actual web server on which your application is running) is temporarily unavailable.
This is generally due to the server being “down” for scheduled maintenance, or to a high traffic load that prevents it from properly servicing all incoming requests.
Redo the website – One of the easiest options, whether you or a manager can do so, is simply to restart the program running the webserver.
Unforeseeable maintenance control – You may not know it, but you may configure your server and/or program automatically to support it.