# 1m\_bad\_requests **URL:** \ **Category:** Alerts\ **Created:** [November 3, 2021, 3:38pm UTC](https://community.netdata.cloud/t/1m-bad-requests/1933 "2021-11-03T15:38:47Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![Tasos\_Katsoulas](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.netdata.cloud/tasos_katsoulas/32/1344_2.png) [@Tasos\_Katsoulas](https://community.netdata.cloud/u/Tasos_Katsoulas)\ **Post date:** [November 3, 2021, 3:38pm UTC](https://community.netdata.cloud/t/1m-bad-requests/1933/1 "2021-11-03T15:38:47Z")
# 1m\_bad\_requests **Web Server | Web log** HTTP response status codes indicate whether a specific HTTP request has been successfully completed or not. The 4xx class of status code is intended for cases in which the client seems to have erred. 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. These status codes are applicable to any request method. [1](https://datatracker.ietf.org/doc/html/rfc2616#section-10.4) The Netdata Agent calculates the ratio of client error HTTP requests over the last minute. This metric does not include the 401 errors. > **Client error responses (4XX)** > > The client error codes below contain the descriptions as provided by Mozilla. > [2](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status#client_error_responses) > > - _400 Bad Request_: The server could not understand the request due to invalid syntax. > > - _401 Unauthorized_: Although the HTTP standard specifies “unauthorized”, semantically this > response means “unauthenticated”. That is, the client must authenticate itself to get the > requested response. > > - _402 Payment Required_: This response code is reserved for future use. The initial aim for > creating this code was using it for digital payment systems, however this status code is used very > rarely and no standard convention exists. > > - _403 Forbidden_: The client does not have access rights to the content; that is, it is > unauthorized, so the server is refusing to give the requested resource. Unlike 401 Unauthorized, > the client’s identity is known to the server. > > - _404 Not Found_: The server can not find the requested resource. In the browser, this means the > URL is not recognized. In an API, this can also mean that the endpoint is valid but the resource > itself does not exist. Servers may also send this response instead of 403 Forbidden to hide the > existence of a resource from an unauthorized client. This response code is probably the most well > known due to its frequent occurrence on the web. > > - _405 Method Not Allowed_: The request method is known by the server but is not supported by the > target resource. For example, an API may not allow calling DELETE to remove a resource. > > - _406 Not Acceptable_: This response is sent when the web server, after performing server-driven > content negotiation, doesn’t find any content that conforms to the criteria given by the user > agent. > > - _407 Proxy Authentication Required_: This is similar to 401 Unauthorized but authentication is > needed to be done by a proxy. > > - _408 Request Timeout_: This response is sent on an idle connection by some servers, even without > any previous request by the client. It means that the server would like to shut down this unused > connection. This response is used much more since some browsers, like Chrome, Firefox 27+, or IE9, > use HTTP pre-connection mechanisms to speed up surfing. Also note that some servers merely shut > down the connection without sending this message. > > - _409 Conflict_: This response is sent when a request conflicts with the current state of the > server. > > - _410 Gone_: This response is sent when the requested content has been permanently deleted from > server, with no forwarding address. Clients are expected to remove their caches and links to the > resource. The HTTP specification intends this status code to be used for “limited-time, > promotional services”. APIs should not feel compelled to indicate resources that have been deleted > with this status code. > > - _411 Length Required_: Server rejected the request because the Content-Length header field is not > defined and the server requires it. > > - _412 Precondition Failed_: The client has indicated preconditions in its headers which the server > does not meet. > > - _413 Payload Too Large_: Request entity is larger than limits defined by server. The server might > close the connection or return an Retry-After header field. > > - _414 URI Too Long_: The URI requested by the client is longer than the server is willing to > interpret. > > - _415 Unsupported Media Type_: The media format of the requested data is not supported by the > server, so the server is rejecting the request. > > - _416 Range Not Satisfiable_: The range specified by the Range header field in the request cannot > be fulfilled. It’s possible that the range is outside the size of the target URI’s data. > > - _417 Expectation Failed_: This response code means the expectation indicated by the Expect request > header field cannot be met by the server. > > - _418 I’m a teapot_: The server refuses the attempt to brew coffee with a teapot. > > - _421 Misdirected Request_: The request was directed at a server that is not able to produce a > response. This can be sent by a server that is not configured to produce responses for the > combination of scheme and authority that are included in the request URI. > > - _422 Unprocessable Entity (WebDAV)_: > The request was well-formed but was unable to be followed due to semantic errors. > > - _423 Locked (WebDAV)_: > The resource that is being accessed is locked. > > - _424 Failed Dependency (WebDAV)_: > The request failed due to failure of a previous request. > > - _425 Too Early_: Indicates that the server is unwilling to risk processing a request that might be > replayed. > > - _426 Upgrade Required_: The server refuses to perform the request using the current protocol but > might be willing to do so after the client upgrades to a different protocol. The server sends an > Upgrade header in a 426 response to indicate the required protocol(s). > > - _428 Precondition Required_: The origin server requires the request to be conditional. This > response is intended to prevent the ‘lost update’ problem, where a client GETs a resource’s state, > modifies it and PUTs it back to the server, when meanwhile a third party has modified the state on > the server, leading to a conflict. > > - _429 Too Many Requests_: The user has sent too many requests in a given amount of time (“rate > limiting”). > > - _431 Request Header Fields Too Large_: The server is unwilling to process the request because its > header fields are too large. The request may be resubmitted after reducing the size of the request > header fields. > > - _451 Unavailable For Legal Reasons_: The user agent requested a resource that cannot legally be > provided, such as a web page censored by a government. > **References and sources** > > 1. [https://datatracker.ietf.org/doc/html/rfc2616#section-10.4](https://datatracker.ietf.org/doc/html/rfc2616#section-10.4) > 2. [https://developer.mozilla.org/en-US/docs/Web/HTTP/Status#client\_error\_responses](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status#client_error_responses) ### 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 server logs for more details about how the server is handling the requests. For example, web servers such as Apache or Nginx produce two files called access.log and error.log (by default under `/var/log/{nginx, apache2}/{access.log, error.log}`) > **Troubleshoot 404 codes in the server side** > > The 404 requests indicate outdated links on your website or in other websites that redirect to your website. To check for dead links on your on website, use a `broken link checker` software periodically.