postgresql-11主从复制（流复制）部署

• 主从机器分配

  • IP地址	DB版本	主从关系
    192.168.63.134	11.6	主
    192.168.63.141	11.6	从

•  

  安装postgresql

  • 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

• 主库配置

  • 主库初始化

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

  • 创建复制用户，进行主从同步使用

    • [root@localhost data]# sudo -i -u postgres
      -bash-4.2$ psql
      psql (11.6)
      输入 "help" 来获取帮助信息.
      
      postgres=# create role repl login replication encrypted password '123456';
      CREATE ROLE

  • 主库上配置从库采用repl账号

    • vim /var/lib/pgsql/11/data/pg_hba.conf
      
      #只需要台添加下面两行，repl是用来做备份的用户，后面的192.168.63.0/24是该网段内的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，要创建刚刚配置的一些目录结构：

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

    • 重启主库服务

    • systemctl restart postgresql-11

• 从库配置

  • 从库安装完成后，不初始化，若已经初始化，删除其data目录

  • #把主节点所有的数据文件都会拷贝过来
    [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 表空间
    [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

  • 从库配置文件，根据下面的配置进行修改。

    [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,

  • 创建恢复文件recovery.conf。

    • [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
      
      # 调整参数：
      recovery_target_timeline = 'latest'   #同步到最新数据
      standby_mode = on          #指明从库身份
      trigger_file = 'failover.now'
      primary_conninfo = 'host=192.168.63.134 port=5432 user=repl password=123456'   #连接到主库信息

    • 启动从库

      systemctl start postgresql-11

  • 验证主从配置
    • 在主库上运行以下命令

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

  • 可以创建一个数据库自行验证