Diameter connection closed

Logged when a Diameter connection that was its adjacency's Open connection stops. diameter_connection_direction shows which side established it. diameter_close_cause is one of:

• disconnect-request-received: the peer sent DPR and Radiator answered it.
• disconnect-answer-received: the peer answered the DPR that Radiator sent while stopping or reloading the server.
• local-shutdown: Radiator closed the connection because the server is stopping or reloading.
• not-selected: connection election or a replacement connection took over the adjacency.
• peer-closed-transport: the peer closed the TCP or TLS connection without DPR.
• transport-error, disconnect-answer-timeout, watchdog-timeout, or peer-protocol-violation: the connection failed; a separate event with the same connection fields explains the failure.

No action for disconnect-request-received, disconnect-answer-received, local-shutdown, or not-selected. For peer-closed-transport, which has no separate failure event, check the peer's logs and any firewall or load balancer between the nodes. For the other causes, check the related failure event and the peer.