yum install https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm -y
yum install postgresql11 -y
yum install postgresql11-server -y

主庫初始化

• /usr/pgsql-11/bin/postgresql-11-setup initdb
   
  systemctl start postgresql-11

• [root@localhost data]# sudo -i -u postgres
  -bash-4.2$ psql
  psql (11.6)
  輸入 "help" 來獲取幫助資訊.
  
  postgres=# create role repl login replication encrypted password '123456';
  CREATE ROLE

• vim /var/lib/pgsql/11/data/pg_hba.conf
  
  #只需要臺新增下面兩行，repl是用來做備份的使用者，後面的192.168.63.0/24是該網段內的IP地址
  host    replication     repl            192.168.63.0/24         md5
  host    all             repl            192.168.63.0/24         trust
  
  vim /var/lib/pgsql/11/data/postgresql.conf 
  
  listen_addresses = '*'            # what IP address(es) to listen on;
  port = 5432                # (change requires restart)
  max_connections = 512            # (change requires restart)
  shared_buffers = 128MB            # min 128kB
  dynamic_shared_memory_type = posix    # the default is the first option
  wal_level = hot_standby        # minimal, replica, or logical
  archive_mode = on        # enables archiving; off, on, or always
  archive_command = 'cp %p /var/lib/pgsql/11/data/pg_archive/%f'        # command to use to archive a logfile segment
  max_wal_senders = 6        # max number of walsender processes
  wal_keep_segments = 10240    # in logfile segments, 16MB each; 0 disables
  wal_sender_timeout = 60s    # in milliseconds; 0 disables
  log_directory = 'log'    # directory where log files are written
   
  

• 修改完，要建立剛剛配置的一些目錄結構：

• mkdir /var/lib/pgsql/11/data/pg_archive/
  chown -R postgres.postgres /var/lib/pgsql/11/data

• 重啟主庫服務

• systemctl restart postgresql-11

#把主節點所有的資料檔案都會拷貝過來
[root@localhost ~]# pg_basebackup -h 192.168.63.134 -U repl -D /var/lib/pgsql/11/data/ -X stream -P
口令: 
25312/25312 kB (100%), 1/1 表空間
[root@localhost ~]# ls /var/lib/pgsql/12/data/
backup_label  current_logfiles  log         pg_commit_ts  pg_hba.conf    pg_logical    pg_notify    pg_serial     pg_stat      pg_subtrans  pg_twophase  pg_wal   postgresql.auto.conf
base          global            pg_archive  pg_dynshmem   pg_ident.conf  pg_multixact  pg_replslot  pg_snapshots  pg_stat_tmp  pg_tblspc    PG_VERSION   pg_xact  postgresql.conf
 

[root@localhost ~]# vim /var/lib/pgsql/11/data/postgresql.conf
listen_addresses = '*'            # what IP address(es) to listen on;
port = 5432                # (change requires restart)
max_connections = 1000            # (change requires restart)
shared_buffers = 128MB            # min 128kB
dynamic_shared_memory_type = posix    # the default is the first option
wal_level = replica        # minimal, replica, or logical
archive_mode = on        # enables archiving; off, on, or always
archive_command = 'cp %p /var/lib/pgsql/12/data/pg_archive/%f'        # command to use to archive a logfile segment
wal_sender_timeout = 60s    # in milliseconds; 0 disables
hot_standby = on            # "on" allows queries during recovery
max_standby_streaming_delay = 30s    # max delay before canceling queries
wal_receiver_status_interval = 10s    # send replies at least this often
hot_standby_feedback = on        # send info from standby to prevent
log_directory = 'log'    # directory where log files are written,

• [root@localhost 11]# cp /usr/pgsql-11/share/recovery.conf.sample /var/lib/pgsql/11/data/recovery.conf
  [root@localhost 11]# vim /var/lib/pgsql/11/data/recovery.conf
  
  # 調整引數：
  recovery_target_timeline = 'latest'   #同步到最新資料
  standby_mode = on          #指明從庫身份
  trigger_file = 'failover.now'
  primary_conninfo = 'host=192.168.63.134 port=5432 user=repl password=123456'  #連線到主庫資訊

• 啟動從庫

  systemctl start postgresql-11

• 在主庫上執行以下命令

  postgres=# select client_addr,sync_state from pg_stat_replication;
    client_addr   | sync_state 
  ----------------+------------
   192.168.63.141 | async
  (1 行記錄)