Обсуждение: BDR: cannot remove node from group
Testing BDR for the first time, using the binary packages for Ubuntu 10.04 provided at http://packages.2ndquadrant.com/bdr/apt/ Postgres 9.4.4 and BDR 0.9.2 (I think) I'm loosely following this document: http://bdr-project.org/docs/stable/quickstart-enabling.html Except I've created two separate instances and I'm trying to replicate between instances. I've created the bdrdemo database, and then I've created the extensions: CREATE EXTENSION btree_gist; CREATE EXTENSION bdr; Then I did bdr_group_create on one node: SELECT bdr.bdr_group_create( local_node_name := 'pg-test1-dev-uswest2-aws', node_external_dsn := 'port=5432 dbname=bdrdemo' ); But then I've realized I need a host statement in node_external_dsn. So now I'm trying to remove this node: SELECT bdr.bdr_part_by_node_names('{pg-test1-dev-uswest2-aws}'); But if I try to re-add it with the new parameters: SELECT bdr.bdr_group_create( local_node_name := 'pg-test1-dev-uswest2-aws', node_external_dsn := 'host=pg-test1-dev-uswest2-aws port=5432 dbname=bdrdemo' ); I get this: ERROR: This node is already a member of a BDR group HINT: Connect to the node you wish to add and run bdr_group_join from it instead What do I need to do to start over? I want to delete all traces of the BDR configuration I've done so far. -- Florin Andrei http://florin.myip.org/
On 26 August 2015 at 07:19, Florin Andrei <florin@andrei.myip.org> wrote: > What do I need to do to start over? I want to delete all traces of the BDR > configuration I've done so far. you need to DROP the database you removed, then re-create it as a new empty database. You cannot re-join a node that has been removed. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
On 2015-08-25 18:29, Craig Ringer wrote: > On 26 August 2015 at 07:19, Florin Andrei <florin@andrei.myip.org> > wrote: > >> What do I need to do to start over? I want to delete all traces of the >> BDR >> configuration I've done so far. > > you need to DROP the database you removed, then re-create it as a new > empty database. You cannot re-join a node that has been removed. postgres=# DROP DATABASE bdrdemo; ERROR: database "bdrdemo" is being accessed by other users DETAIL: There is 1 other session using the database. Something's holding it open, not sure exactly what. -- Florin Andrei http://florin.myip.org/
On 2015-09-15 16:45, Florin Andrei wrote: > On 2015-08-25 18:29, Craig Ringer wrote: >> On 26 August 2015 at 07:19, Florin Andrei <florin@andrei.myip.org> >> wrote: >> >>> What do I need to do to start over? I want to delete all traces of >>> the BDR >>> configuration I've done so far. >> >> you need to DROP the database you removed, then re-create it as a new >> empty database. You cannot re-join a node that has been removed. > > postgres=# DROP DATABASE bdrdemo; > ERROR: database "bdrdemo" is being accessed by other users > DETAIL: There is 1 other session using the database. > > Something's holding it open, not sure exactly what. More specifically, it seems like it's the bgworker that's holding that DB: 1123 ? S 0:00 /usr/lib/postgresql/9.4/bin/postgres -D /var/lib/postgresql/9.4/main -c config_file=/etc/postgresql/9.4/main/postgresql.conf 1124 ? Ss 0:00 \_ postgres: logger process 1126 ? Ss 0:00 \_ postgres: checkpointer process 1127 ? Ss 0:00 \_ postgres: writer process 1128 ? Ss 0:00 \_ postgres: wal writer process 1129 ? Ss 0:00 \_ postgres: autovacuum launcher process 1130 ? Ss 0:00 \_ postgres: stats collector process 1136 ? Ss 0:00 \_ postgres: bgworker: bdr supervisor 1137 ? Ss 0:00 \_ postgres: bgworker: bdr db: bdrdemo Should I just kill that process, or is there a "nicer" way to do it? More generally, is there a way to just turn off BDR entirely on one node? I can't find a clear answer in the documentation to questions like - how do I turn on or off replication altogether? -- Florin Andrei http://florin.myip.org/