Re: BDR node removal and rejoin

["Zhu, Joshua" <jzhu@xxxxxxxxxxxxx>]

An update… after manually removing the record for ‘node4’ from bdr.bdr_nodes, corresponding record in bdr.bdr_connections, and associated replication slot (with pg_drop_replication_slot), rejoining was successful.

 

I was under the impression that there is no need to perform manual cleanup before a removed node (with database dropped and recreated) rejoining a BDR group.

 

From: Zhu, Joshua
Sent: Friday, July 07, 2017 2:59 PM
To: 'pgsql-general@xxxxxxxxxxxxxx' <pgsql-general@xxxxxxxxxxxxxx>
Subject: BDR node removal and rejoin

 

Hi, I am having difficulty removing a node from a BDR group (with nodes node1 through node5) then rejoin the group.

 

Prior to removing a node, the BDR is running fine, query on bdr.bdr_nodes table shows all nodes having the status ‘r’.

 

Here is what I have done for removing node5 and rejoining:

 

• On node1, do bdr.bdr_part_by_node_names

 

At this point the status of node5 in bdr.bdr_nodes becomes ‘k’

 

• On node5, do bdr.remove_bdr_from_local_node
• On node5, drop and recreate the database, then rejoin using bdr.bdr_group_join (using the same node name and external dsn)

 

At this point the status of node5 on node1 though node4 still remains ‘k’, and the status of node5 on node5 (there is only one record) is ‘i’, and they stuck at these status codes.

[note: I tried using a different node name on rejoining, same result]

 

What have I done wrong, what is the correct way of doing removal and rejoining?

 

Thanks