Web Server | Web log

HTTP response status codes indicate whether a specific HTTP request has been successfully completed or not.

Response status codes beginning with the digit “5” indicate cases in which the server is aware that it has erred or is incapable of performing the request. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. User agents should display any included entity to the user. These response codes are applicable to any request method.1

The Netdata Agent calculates the ratio of server error HTTP requests over the last minute.

Server error responses (5XX)

The error codes below contain the descriptions as provided by
Mozilla. 2

  • 500 Internal Server Error: The server has encountered a situation it does not know how to

  • 501 Not Implemented: The request method is not supported by the server and cannot be handled.
    The only methods that servers are required to support (and therefore that must not return this
    code) are GET and HEAD.

  • 502 Bad Gateway: This error response means that the server, while working as a gateway to get a
    response needed to handle the request, got an invalid response.

  • 503 Service Unavailable: The server is not ready to handle the request. Common causes are a
    server that is down for maintenance or that is overloaded. Note that together with this response,
    a user-friendly page explaining the problem should be sent. This response should be used for
    temporary conditions and the Retry-After HTTP header should, if possible, contain the estimated
    time before the recovery of the service. The webmaster must also take care about the
    caching-related headers that are sent along with this response, as these temporary condition
    responses should usually not be cached.

  • 504 Gateway Timeout: This error response is given when the server is acting as a gateway and
    cannot get a response in time.

  • 505 HTTP Version Not Supported: The HTTP version used in the request is not supported by the

  • 506 Variant Also Negotiates: The server has an internal configuration error: the chosen variant
    resource is configured to engage in transparent content negotiation itself, and is therefore not a
    proper end point in the negotiation process.

  • 507 Insufficient Storage (WebDAV):
    The method could not be performed on the resource because the server is unable to store the
    representation needed to successfully complete the request.

  • 508 Loop Detected (WebDAV):
    The server detected an infinite loop while processing the request.

  • 510 Not Extended: Further extensions to the request are required for the server to fulfill it.

  • 511 Network Authentication: Required Indicates that the client needs to authenticate to gain
    network access.

Source: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status#server_error_responses

References and sources
  1. Server errors on Datatracker

  2. HTTP server errors on Mozilla

Troubleshooting section:

General approach

To identify the HTTP response code your web server sends back:

  1. Open the Netdata dashboard.
  2. Inspect the detailed_response_codes chart for your web server. This chart keeps track of exactly what error codes your web server sends out.

You should also check the server error logs. For example, web servers such as Apache or Nginx produce and error logs, by default under /var/log/{nginx, apache2}/{access.log, error.log}

Troubleshoot 500 error code

One of the things that can cause HTTP 500 response errors is a misconfiguration in the .htaccess file of your web server.