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HTTP 501 Not Implemented

The server does not support this feature. Free reference, no signup.

501 Not Implemented

MeaningThe server does not support this feature.
WhenThe method or feature is recognized and deliberately not built.
CausesA stub route or an HTTP method the server never implemented.
FixStop calling it, or implement the feature.
RetryDo not retry.
Alert?Usually no. Alert if a route that used to work now returns 501.

Runs in your browser. Nothing you enter is stored.

Most 501s are not an incident

Alert if a route that used to work now returns 501.

curl -sS -X POST https://api.trigv.com/v1/events \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "Authorization: Bearer $TRIGV_API_KEY" \
  -d '{"channel":"ops","title":"HTTP 501","level":"warning"}'
Get an API key All status codes

How to use it

  1. Read what 501 means before changing a retry loop.
  2. Check the common causes against the response body and the server log.
  3. Follow the retry note. Retrying a 400 with the same body will fail again.
  4. Alert only in the cases the verdict describes.

About this tool

HTTP 501 Not Implemented means The server does not support this feature. Servers send it when The method or feature is recognized and deliberately not built.

Common causes: A stub route or an HTTP method the server never implemented. The practical fix is: Stop calling it, or implement the feature.

Retry: Do not retry.

Alert on it? Usually no. Alert if a route that used to work now returns 501.

Trigv is a push for the moment a status starts mattering, not a log of every response. If the code is one you should hear about, the snippet posts a single event with level error or warning. The status page itself does not call your API.

Questions

What is HTTP 501?

The server does not support this feature.

Should the client retry?

Do not retry.

Should I alert on it?

Usually no. Alert if a route that used to work now returns 501.

How is this different from reading the spec?

The page adds a plain retry note and an alert verdict for people running the service, not only for people parsing the response.

500 Internal Server Error The server hit an unexpected error. 502 Bad Gateway A proxy got an invalid response from the upstream server. 503 Service Unavailable The server cannot handle the request right now. Cron Job Alert Script Wrap a command so a failed, slow, or finished cron job sends a Trigv alert.