postgresql主从备份_Postgresql主从热备配置

软件环境

CentOS5.1

Postgresql  9.4.10

一、 安装postgreSQL

1.YUM自动获取版本

SHELL>wget --no-check-certificate https://yum.postgresql.org/9.4/redhat/rhel-5-x86_64/pgdg-redhat94-9.4-1.noarch.rpm

SHELL>rpm -ivh pgdg-redhat94-9.4-1.noarch.rpm

SHELL>yum install postgresql94-server postgresql94-contrib

2.初始化数据库

SHELL>/etc/init.d/postgresql-9.4 initdb

3.启动数据库

SHELL>/etc/init.d/postgresql-9.4 start

4.进入数据库

SHELL>su  postgres

SHELL>psql

5.修改密码

SQL>alter user postgres with password &＃39;postgres&＃39;;

6.启动服务

SHELL>service postgresql-9.4 restart

二、配置过程

主机IP:server.example.com

从机IP:client.example.com

数据库&＃xff1a;postgres

用户名&＃xff1a;postgres

密  码&＃xff1a;postgres

1. 主机pg_hba.conf添加备份主从数据库

# IPv4 local connections

host    replication     postgres        client.example.com/32         trust

host    replication     postgres        server.example.com/32         trust

2. 主机postgresql.conf配置(‘#’非必须)

wal_level &＃61; hot_standby #开启主从热备模式

max_wal_senders &＃61; 10      #从机可连接数

wal_keep_segments &＃61; 32

#check_function_bodies &＃61; on

#checkpoint_segments &＃61; 16

#hot_standby &＃61; on

#hot_standby_feedback &＃61; on

#autovacuum &＃61; on

#fsync &＃61; on #异步数据同步

#full_page_writes &＃61; on

#archive_mode &＃61; on #打开归档模式

#archive_command &＃61; &＃39;cp %p /var/lib/pgsql/9.4/data/pg_archive/%f&＃39;

#将归档文件保存在data/archive目录下

#log_destination &＃61; &＃39;csvlog&＃39;

#logging_collector &＃61; on

#log_directory &＃61; &＃39;/var/log/pgsql-log/&＃39;

#log_filename &＃61; &＃39;postgresql-%Y-%m-%d_%H%M%S.log&＃39;

#log_truncate_on_rotation &＃61; on

#log_rotation_age &＃61; 1d

#log_rotation_size &＃61; 10MB

#log_min_duration_statement &＃61; 1000

#log_lock_waits &＃61; on

#log_statement &＃61; &＃39; ddl &＃39;

#log_timezone &＃61; &＃39;PRC&＃39;

#log_autovacuum_min_duration &＃61; 0

3. 建立归档文件和日志文件

SHELL>mkdir /var/lib/pgsql/9.4/data/pg_archive

SHELL>chown -R postgres.postgres /var/lib/pgsql/9.4/data/pg_archive

SHELL>mkdir /var/log/pgsql-log

SHELL>chown -R postgres.postgres /var/log/pgsql-log

4. 重启动服务

SHELL>service postgresql-9.4 restart

5. 基础备份

SQL> select pg_start_backup(&＃39;&＃39;);

6. 从数据库删除 data目录

SHELL>rm -rf /var/lib/pgsql/9.4/data

7. 拷贝主数据库至从服务器

SHELL>scp -rp /var/lib/pgsql/9.4/data root&＃64;client.example.com:/var/lib/pgsql/9.4/

SHELL>chown -R postgres.postgres /var/lib/pgsql/9.4/data

8. 结束主数据库的备份状态

SQL> select pg_stop_backup();

9. 查看是否成功归档

SHELL>cd /var/lib/pgsql/9.4/data/pg_archive

SHELL>ls

10. 移动归档文件到从机

SHELL>scp -rp /var/lib/pgsql/9.4/data/pg_archive root&＃64;client.example.com:/var/lib/pgsql/9.4/data/

SHELL>chown -R postgres.postgres /var/lib/pgsql/9.4/data/pg_archive

11. 从机数据库配置

SHELL>mkdir /var/log/pgsql-log

SHELL>chown -R postgres.postgres /var/log/pgsql-log

postgresql.conf 设置hot_standby &＃61; on

12. 添加recovery.conf文件(在$PG_HOME/share里&＃xff0c;用户组postgresql)&＃xff0c;并录入以下内容

restore_command &＃61; &＃39;cp /var/lib/pgsql/9.4/data/pg_archive/%f %p&＃39;

standby_mode &＃61; on

primary_conninfo &＃61; &＃39;host&＃61;server.example.com port&＃61;5432 user&＃61;postgres password&＃61;postgres&＃39;

trigger_file &＃61; &＃39;/trigger.postgres&＃39;(任意值)

13. 删除从数据库postmaster.pid文件以及pg_xlog下的文件,并重新启动服务

SHELL>rm /var/lib/pgsql/9.4/data/postmaster.pid

SHELL>rm -rf /var/lib/pgsql/9.4/data/pg_xlog/*

SHELL>service postgresql-9.4 restart

13.验证是否配置成功并确定主从机

①.主机表中能查到记录&＃xff0c;从机表中没有

SQL>select * from pg_stat_replication;

√②.根据psql自带函数判断&＃xff0c;主机f 从机t

SQL>select pg_is_in_recovery();

√③. 查看postgresql线程&＃xff0c;wal sender是主机&＃xff0c;wal receiver是从机

SHELL>ps -ef|grep postgres

如果都验证失败&＃xff0c;可以setup命令关闭防火墙再次验证

14. 主从切换

①.关闭主机服务

SHELL>service postgresql-9.4 stop

有trigger_file触发文件则删除

SHELL>rm  trigger_file文件

从机进行验证(结果应该无wal receiver项)

SHELL>ps -ef|grep postgres

②.触发从机为主机

SHELL>touch  trigger_file文件

验证(应包含autovacuum项且recovery文件后缀变为done)

SHELL>ps –ef|grep postgres

③.建立新从机&＃xff0c;以下选一种方式

(一)按主从热备配置新建

(二)复制新主机的recovery.conf文件&＃xff0c;并修改配置

Ⅰprimary_conninfo信息

Ⅱ添加recovery_target_timeline &＃61; &＃39;latest&＃39;(不加会有timeline时间线问题)

Ⅲ重命名唯一trigger_file  然后同步归档文件

SHELL>scp -rp /var/lib/pgsql/9.4/data/pg_archive root&＃64;server.example.com:/var/lib/pgsql/9.4/data

SHELL>chown postgres:postgres /var/lib/pgsql/9.4/data

④.启动新从机

SHELL>service postgresql-9.4 start

三、部分问题记录

could not connect to the primary server 关闭防火墙

server closed the connection unexpectedly启动postgreSQL服务/var/lib/pgsql权限需为700

参考博客