HTTP 409 Conflict: Meaning and Fix

409 Conflict

Meaning	The request conflicts with the current state of the resource.
When	A duplicate unique key, a version mismatch, or an edit against stale data.
Causes	Two writers updating the same record.
Fix	Reload the resource and retry the edit with the new version.
Retry	Retry only after resolving the conflict.
Alert?	Usually no. Occasional conflicts are normal. A burst can mean a bad deploy.

Runs in your browser. Nothing you enter is stored.

Most 409s are not an incident

Occasional conflicts are normal. A burst can mean a bad deploy.

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 409","level":"warning"}'

Get an API key All status codes

How to use it

Read what 409 means before changing a retry loop.
Check the common causes against the response body and the server log.
Follow the retry note. Retrying a 400 with the same body will fail again.
Alert only in the cases the verdict describes.

About this tool

HTTP 409 Conflict means The request conflicts with the current state of the resource. Servers send it when A duplicate unique key, a version mismatch, or an edit against stale data.

Common causes: Two writers updating the same record. The practical fix is: Reload the resource and retry the edit with the new version.

Retry: Retry only after resolving the conflict.

Alert on it? Usually no. Occasional conflicts are normal. A burst can mean a bad deploy.

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 409?

The request conflicts with the current state of the resource.

Should the client retry?

Retry only after resolving the conflict.

Should I alert on it?

Usually no. Occasional conflicts are normal. A burst can mean a bad deploy.

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.

400 Bad Request The server could not understand the request. 401 Unauthorized The request is missing valid authentication. 403 Forbidden The server understood the request and refuses it. Cron Job Alert Script Wrap a command so a failed, slow, or finished cron job sends a Trigv alert.

HTTP 409 Conflict