You can use repmgr on a running node on your cluster to unregister a failed or unreachable standby node.
To unregister a standby node that is not running, you must provide the node ID. To find the IP address, check the status of the cluster and locate the node. On that row, use the host value from the Connection string column to identify the IP address of the node. See Check the Status of a Database High Availability Cluster.
- Log in or SSH as root to the OS of any of the running nodes of the cluster.
- Change the user to postgres.
sudo -i -u postgres
- Unregister the failed or unreachable node.
/opt/vmware/vpostgres/current/bin/repmgr standby unregister -f /opt/vmware/vpostgres/current/etc/repmgr.conf --node-id=ID