1、异步流复制简单配置示例

服务器规划

192.168.0.130(主库)

192.168.0.131(备库)

192.168.0.132(备库)

主节点配置

1、初始化数据集簇

./initdb ../data-primary -U postgres

2、启动服务，创建用户

ALTER USER postgres WITH PASSWORD ‘123456‘;
CREATE ROLE repl WITH PASSWORD ‘123456‘ REPLICATION LOGIN;

3、配置 postgresql.conf

listen_addresses=‘*‘
archive_mode=on
archive_command=‘cp "%p" "/data/pg12/archivedir"‘
max_wal_senders=10
max_replication_slots=10
wal_level=replica
wal_keep_segments=512
hot_standby=on
synchronous_commit=on
synchronous_standby_names=‘any 1(*)‘
logging_collector = on
log_destination = ‘csvlog‘
log_truncate_on_rotation = on
log_filename = ‘postgresql-%w.log‘
log_connections = off
log_disconnections = off
log_error_verbosity = verbose
log_statement = ddl
log_min_duration_statement = 3s
log_checkpoints = on

4、配置 pg_hba.conf

host    replication     all             0.0.0.0/0            trust

5、重启服务

node1备节点配置

1、删除备机data目录

   rm -rf /data/pg12/pgdata

2、基础备份

pg_basebackup -h 192.168.0.130 -p 5432 -U repl -D /data/pg12/pgdata/ -v -P -R -X stream -C -S node1

在pgdata路径下会生成：standby.signal 文件

在pgdata路径下： postgresql.auto.conf 文件会添加连接信息

[ data-standby01]$ cat postgresql.auto.conf 
# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command.
primary_conninfo = ‘user=repl password=123456 host=192.168.0.130 port=5432 sslmode=disable sslcompression=0 gssencmode=disable target_session_attrs=any‘

2、启动备库（同一服务器实验，需要先修改 postgresql.conf 的端口）

node2备节点配置

1、基础备份

pg_basebackup -h 192.168.0.130 -p 5432 -U repl -D /data/pg12/pgdata/ -v -P -R -X stream -C -S node2

在pgdata路径下会生成：standby.signal 文件

在pgdata路径下： postgresql.auto.conf 文件会添加连接信息

[ data-standby02]$ cat postgresql.auto.conf 
# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command.
primary_conninfo = ‘user=repl password=123456 host=192.168.0.130 port=5432 sslmode=disable sslcompression=0 gssencmode=disable target_session_attrs=any‘

2、启动备库（同一服务器实验，需要先修改 postgresql.conf 的端口）

查看

postgres=# \x
Expanded display is on.
postgres=# select * from pg_stat_replication ;
-[ RECORD 1 ]----+------------------------------
pid              | 24416
usesysid         | 16384
usename          | repl
application_name | walreceiver
client_addr      | 192.168.0.131
client_hostname  | 
client_port      | 55580
backend_start    | 2020-06-20 18:12:28.701572+08
backend_xmin     | 
state            | streaming
sent_lsn         | 0/5000060
write_lsn        | 0/5000060
flush_lsn        | 0/5000060
replay_lsn       | 0/5000060
write_lag        | 
flush_lag        | 
replay_lag       | 
sync_priority    | 0
sync_state       | quorum
reply_time       | 2020-06-20 18:14:50.806858+08
-[ RECORD 2 ]----+------------------------------
pid              | 24433
usesysid         | 16384
usename          | repl
application_name | walreceiver
client_addr      | 192.168.0.132
client_hostname  | 
client_port      | 55582
backend_start    | 2019-10-28 18:12:33.452452+08
backend_xmin     | 
state            | streaming
sent_lsn         | 0/5000060
write_lsn        | 0/5000060
flush_lsn        | 0/5000060
replay_lsn       | 0/5000060
write_lag        | 
flush_lag        | 
replay_lag       | 
sync_priority    | 0
sync_state       | quorum
reply_time       | 2020-06-20 18:14:53.639337+08

3、同步流复制示例

在异步流复制的基础上：

主库 postgresql.conf 添加配置

synchronous_commit = on
synchronous_standby_names = ‘node1,node2‘

备库 postgresql.auto.conf 修改配置

# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command.
primary_conninfo = ‘application_name=standby01 user=repl password=123456 host=192.168.0.130 port=5432 sslmode=disable sslcompression=0 gssencmode=disable target_session_attrs=any‘

# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command.
primary_conninfo = ‘application_name=standby02 user=repl password=123456 host=192.168.0.130 port=5432 sslmode=disable sslcompression=0 gssencmode=disable target_session_attrs=any‘

重启主、备服务，查看状态

postgres=# \x
Expanded display is on.
postgres=# select * from pg_stat_replication ;
-[ RECORD 1 ]----+------------------------------
pid              | 24880
usesysid         | 16384
usename          | repl
application_name |node2
client_addr      | 192.168.0.132
client_hostname  | 
client_port      | 55598
backend_start    | 2020-06-20 18:25:09.462092+08
backend_xmin     | 
state            | streaming
sent_lsn         | 0/60000D8
write_lsn        | 0/60000D8
flush_lsn        | 0/60000D8
replay_lsn       | 0/60000D8
write_lag        | 
flush_lag        | 
replay_lag       | 
sync_priority    | 2
sync_state       | potential
reply_time       | 2020-06-20 18:25:29.613489+08
-[ RECORD 2 ]----+------------------------------
pid              | 24858
usesysid         | 16384
usename          | repl
application_name | node1
client_addr      | 192.168.0.131
client_hostname  | 
client_port      | 55596
backend_start    | 2020-06-20 18:25:06.144197+08
backend_xmin     | 
state            | streaming
sent_lsn         | 0/60000D8
write_lsn        | 0/60000D8
flush_lsn        | 0/60000D8
replay_lsn       | 0/60000D8
write_lag        | 
flush_lag        | 
replay_lag       | 
sync_priority    | 1
sync_state       | sync
reply_time       | 2020-06-20 18:25:26.282327+08