The bdr.bdr_nodes table keeps track of a node's membership in a BDR group. A row is inserted or updated in the table during the node join process, and during node removal.
The 'status' column may have the following values, which are subject to change:
r- Ready: The node can function fully. Slots may be created on this node and it can participate with the BDR group.
b- Joining: The node is bootstrapping. This state occurs when join has been initiated but a copy has not yet been begun.
i- Joining: The node is doing initial slot creation or an initial dump and load
c- Joining: The node is catching up to the target node and is not yet ready to participate with the BDR group.
o- Joining: The node has caught up with the target node and is waiting for all inbound and outbound slots to be created.
k- Parting/Parted: The node has been 'killed' or removed by the user with the function bdr.bdr_part_by_node_names.
Note that the status doesn't indicate whether the node is actually up right now. A node may be shut down, isolated from the network, or crashed and still appear as r in bdr.bdr_nodes because it's still conceptually part of the BDR group. Check pg_stat_replication and pg_replication_slots for the connection and replay status of a node. See Monitoring.
Do not directly modify bdr.bdr_nodes. Use the provided node management functions instead. See Node management functions.