Errors and Response Codes


General Tips

  • make sure the load tested URL is up and publicly available before running any load or performance tests
  • check the HTTP method (GET is the request done by browsers when accessing a website or an API endpoint)
  • start with a small number of clients (25-50 clients) and check the number of errors
  • try to increase the number of the clients gradually to understand how your API, Website or WebApp behaves
  • check the Time, Latency, Hits, Throughput and Errors for each test to check the performances of your system

3xx response codes (redirection)

  • if the URL added for the load test is doing any redirects to another URL
  • if you are testing the redirection, try to do the load test on the final URL, after the redirects end
  • remove the “Follow redirects” checkbox next to the URL if you want to avoid redirecting your requests and do the load test on the URL added

4xx response codes (client side errors)

  • the URL is correct and publicly available
  • check the HTTP Method used: GET, POST, PUT or DELETE (GET is the request done by browsers when accessing a website or an API endpoint)
  • the request headers, cookies, query params or basic HTTP auth params are set correctly

5xx response codes (server side errors)

  • the response code, usually if the load tested API, WebSite, Web or Mobile Application doesn’t handle the load properly you’ll start receiving 503 Service Unavailable responses.
  • try to reduce the number of clients (concurrent users) for your load test and check the boundaries of your system

For more information about how to load test your websites and APIs in the cloud with LoadFocus Load Testing tool, see Load Testing Service or JMeter Load Testing Service.

Response Codes (Full list)

According to (w3schools.com)[https://w3schools.com], here is a list of HTTP status messages that might be returned on running a load test for API Endpoints, WebSites, Web and Mobile Applications:

1xx: Information

  • 100 Continue The server has received the request headers, and the client should proceed to send the request body
  • 101 Switching Protocols The requester has asked the server to switch protocols
  • 103 Checkpoint Used in the resumable requests proposal to resume aborted PUT or POST requests

2xx: Successful

  • 200 OK The request is OK (this is the standard response for successful HTTP requests)
  • 201 Created The request has been fulfilled, and a new resource is created
  • 202 Accepted The request has been accepted for processing, but the processing has not been completed
  • 203 Non-Authoritative Information The request has been successfully processed, but is returning information that may be from another source
  • 204 No Content The request has been successfully processed, but is not returning any content
  • 205 Reset Content The request has been successfully processed, but is not returning any content, and requires that the requester reset the document view
  • 206 Partial Content The server is delivering only part of the resource due to a range header sent by the client

3xx: Redirection

  • 300 Multiple Choices A link list. The user can select a link and go to that location. Maximum five addresses
  • 301 Moved Permanently The requested page has moved to a new URL
  • 302 Found The requested page has moved temporarily to a new URL
  • 303 See Other The requested page can be found under a different URL
  • 304 Not Modified Indicates the requested page has not been modified since last requested
  • 306 Switch Proxy No longer used
  • 307 Temporary Redirect The requested page has moved temporarily to a new URL
  • 308 Resume Incomplete Used in the resumable requests proposal to resume aborted PUT or POST requests

4xx: Client Error

  • 400 Bad Request The request cannot be fulfilled due to bad syntax
  • 401 Unauthorized The request was a legal request, but the server is refusing to respond to it. For use when authentication is possible but has failed or not yet been provided
  • 402 Payment Required Reserved for future use
  • 403 Forbidden The request was a legal request, but the server is refusing to respond to it
  • 404 Not Found The requested page could not be found but may be available again in the future
  • 405 Method Not Allowed A request was made of a page using a request method not supported by that page
  • 406 Not Acceptable The server can only generate a response that is not accepted by the client
  • 407 Proxy Authentication Required The client must first authenticate itself with the proxy
  • 408 Request Timeout The server timed out waiting for the request
  • 409 Conflict The request could not be completed because of a conflict in the request
  • 410 Gone The requested page is no longer available
  • 411 Length Required The “Content-Length” is not defined. The server will not accept the request without it
  • 412 Precondition Failed The precondition given in the request evaluated to false by the server
  • 413 Request Entity Too Large The server will not accept the request, because the request entity is too large
  • 414 Request-URI Too Long The server will not accept the request, because the URL is too long. Occurs when you convert a POST request to a GET request with a long query information
  • 415 Unsupported Media Type The server will not accept the request, because the media type is not supported
  • 416 Requested Range Not Satisfiable The client has asked for a portion of the file, but the server cannot supply that portion
  • 417 Expectation Failed The server cannot meet the requirements of the Expect request-header field

5xx: Server Error

  • 500 Internal Server Error A generic error message, given when no more specific message is suitable
  • 501 Not Implemented The server either does not recognize the request method, or it lacks the ability to fulfil the request
  • 502 Bad Gateway The server was acting as a gateway or proxy and received an invalid response from the upstream server
  • 503 Service Unavailable The server is currently unavailable (overloaded or down)
  • 504 Gateway Timeout The server was acting as a gateway or proxy and did not receive a timely response from the upstream server
  • 505 HTTP Version Not Supported The server does not support the HTTP protocol version used in the request
  • 511 Network Authentication Required The client needs to authenticate to gain network access

Other: Connection Error

The URL added for the load test could not be accessed for one of the following reasons: – the URL is not publicly accessible (we support only URLs which can be accessed publicly via Internet) – the system crashed for some reason