Thanks, sounds like that's something unique in my environment/setup. Here are the results of bdr.bdr_get_local_nodeid() for four nodes in a group, Node 1: (6480169638493465053,1,16386) Node 2: (6480169638493465053,1,20225) Node 3: (6480169638493465053,1,29164) Node 4: (6480169638493465053,1,20227) And here is what pg_replication_slots table looks like on Node 4 bdr_20227_6480169638493465053_1_29164__ | bdr | logical | 20227 | mydb | t | 9603 | | 7750 | 0/2D4E780 | 0/2D4E7B8 bdr_20227_6480169638493465053_1_16386__ | bdr | logical | 20227 | mydb | t | 9602 | | 7750 | 0/2D4E780 | 0/2D4E7B8 bdr_20227_6480169638493465053_1_20225__ | bdr | logical | 20227 | mydb | t | 9601 | | 7750 | 0/2D4E780 | 0/2D4E7B8 -----Original Message----- From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Craig Ringer Sent: Thursday, October 26, 2017 7:24 PM To: Zhu, Joshua <jzhu@xxxxxxxxxxxxxx> Cc: pgsql-general@xxxxxxxxxxxxxx Subject: Re: BDR question on dboid conflicts On 27 October 2017 at 01:15, Zhu, Joshua <jzhu@xxxxxxxxxxxxx> wrote: > Database oid is used in both bdr.bdr_nodes, as node_dboid, and > bdr.bdr_connections, as conn_dboid, also used in construction of > replication slot names. Correct. However, it's used in conjunction with the sysid and node timeline ID. > I noticed that when trying to join a bdr group, if the database oid on > the new node happens to be the same as that of an node already in the > bdr group, the join would fail, and the only way to resolve the > conflict that I was able to come up with has been to retry with > dropping/recreating the database until the dboid does not conflict with any node already in the group. That is extremely surprising. In our regression tests the database oids should be the same quite often, as we do various tests where we create multiple instances. More importantly, every time you bdr_init_copy, you get a clone with the same database oid, and that works fine. There's no detail here to work from, so I cannot guess what's actually happening, but I can confidently say it's not a database oid conflict. Nowhere in BDR should the database oid be considered without the rest of the (sysid,timeline,dboid) tuple. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
