[RETROACTIVE][PAR] Shared RabbitMQ cluster publishers unavailability

The cluster refused publishers messages since 12:32:34 UTC due to a system wide alert that stopped all nodes from accepting publishers messages. This means that RabbitMQ clients would keep trying to publish their messages until the cluster accepted them. The node has been restarted at 17:23 UTC, fixing the issue.

Investigations will be carried out to understand how this happened and why our monitoring did not raise an alert.

The cluster should now be fully operational.