Backend dependency failed

Logged when a backend cannot complete an operation with the server or peer it depends on, and opens or extends the backend's incident. The dependency field identifies what failed:

• HTTP, Duo, YubiKey and RSA AM backends: the configured operation, when a request or OAuth token request fails to connect, fails TLS, times out, or receives an HTTP 5xx or 429 response.
• RADIUS backends: the configured server name, when the server leaves a request unanswered after all retries, over any transport.
• Diameter backends: peer <name> when a peer-group member has no open connection, or native proxy when a proxied request times out, finds no peer with an open connection, exceeds the pending request limit, or fails.

Other failures on the same backend join the existing incident. It is logged only when an alerts block enables backend incidents.

Check the dependency named in the dependency field. For HTTP, check that the endpoint is reachable, its certificate is trusted, and for 5xx or 429 responses the upstream service's health and rate limits. For a RADIUS server, check that it runs, listens on the configured port, and has this server as a client with the same secret. For a Diameter peer, check that it runs and accepts the connection; for native proxy failures, check the peer group's connections and whether its peers answer within the timeout.