I have 2 Centos machine: master, slave (streaming replication). Both of them are built on PostgreSQL 9.3 (image below) and configured failover event (failover PG 9.3 document).
Last WAL in master (pg_xlog):
Last WAL in archive log folder in master:
Last WAL in slave (pg_xlog):
0000000100000002000000D5(3 WALs latency between slave and master) .
recovery.conf file in slave
standby_mode = 'on' primary_conninfo = 'host=10.12.10.108 port=5444 user=enterprisedb password=123456 ' trigger_file = '/tmp/failover' restore_command = 'scp email@example.com:/opt/archivelog/%f "%p"'
Now (3 WALs latency slave & master), the master fails (shutdown by manual) then the slave begin failover procedures..
- Does slave miss 3 WALs(
0000000100000002000000D6, 0000000100000002000000D7, 0000000100000002000000D8) or 1 WAL (
0000000100000002000000D8) after failover ? Why ?
- If I copy all WAL in pg_xlog from master to pg_xlog in slave . Does slave miss WAL after failover? Why ?
- If I copy all WAL in pg_xlog from master to pg_xlog in slave (last WAL in slave:
0000000100000002000000D8) . How slave do a recovery when failover ?
EDIT: I am using pgpool-II 3.4 to control failover between master-slave (failover_command in pgpool.conf).