Horton

Re: [RFC][PATCH] Logical Replication/BDR prototype and architecture

Andres Freund <andres@2ndquadrant.com>

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From: Andres Freund <andres@2ndquadrant.com>
To: pgsql-hackers@postgresql.org
Date: 2012-06-13T17:52:40Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Don't waste the last segment of each 4GB logical log file.

  2. Stamp HEAD as 9.3devel.

  3. Wake WALSender to reduce data loss at failover for async commit.

  4. Make the visibility map crash-safe.

Hi,

The patch as of yet doesn't contain how you actually can use the prototype... 
Obviously at this point its not very convenient:

I have two config files:
Node 1:
port = 5501
wal_level = logical
max_wal_senders = 10
wal_keep_segments = 200
multimaster_conninfo = 'port=5502 host=/tmp'
multimaster_node_id = 1

Node 2:
port = 5502
wal_level = logical
max_wal_senders = 10
wal_keep_segments = 200
multimaster_conninfo = 'port=5501 host=/tmp'
multimaster_node_id = 2

after initdb'ing the first cluster (initdb required):
$ ~/src/postgresql/build/assert/src/backend/postgres -D 
~/tmp/postgres/bdr/1/datadir/ -c 
config_file=~/tmp/postgres/bdr/1/postgresql.conf -c 
hba_file=~/tmp/postgres/bdr/1/pg_hba.conf -c 
ident_file=~/tmp/postgres/bdr/1/pg_ident.conf

$ psql -p 5501 -U andres postgres
CREATE TABLE data(id serial primary key, data bigint);
ALTER SEQUENCE data_id_seq INCREMENT 2;
SELECT setval('data_id_seq', 1);

shutdown cluster

$ rsync -raxv --delete /home/andres/tmp/postgres/bdr/1/datadir/* 
/home/andres/tmp/postgres/bdr/2/datadir

start both cluster which should sync after some output.

$ psql -p 5501 -U andres postgres
SELECT setval('data_id_seq', 2);