服务器主从角色分配
ip db 版本 角色
192.168.2.131 11 主
192.168.2.132 11 从
安装postgresql11
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
登录数据库创建复制用户，进行主从同步使用
create role repl login replication encrypted password '123456';
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192.168.2.0/24是该网段内的IP地址
host replication repl 192.168.2.0/24 md5
host all repl 192.168.2.0/24 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 = replica # 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 = 10 # 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
重启主库服务
systemctl restart postgresql-11
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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
pg_basebackup -h 192.168.2.131 -U repl -D /var/lib/pgsql/11/data/ -X stream -P
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从库配置文件，根据下面的配置进行修改。
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
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=192.168.2.131 port=5432 user=repl password=123456' #连接到主库信息
启动从库
systemctl restart postgresql-11
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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
--------------+------------
192.168.2.132 | async