金庸武功之“”左右互搏术“”postgresql 主从异步流复制配置

Posted 2020-10-06

一.环境准备

a.关闭selinxu

b.关闭iptables

c.centos6.5

d.postgresql9.4.4

master：192.168.1.211

slave:  192.168.1.212

时间同步：

#同步系统时间

  [[email protected] ~]#  rm  -rf  /etc/localtime

  [[email protected] ~]#  ln  -s   /usr/share/zoneinfo/Asia/Shanghai  /etc/localtime

  [[email protected] ~]#  yum   install  -y  ntpdate

  [[email protected] ~]#  /usr/sbin/ntpdate -u 202.120.2.101 && hwclock -w

   

  [[email protected] ~]# systemctl enable ntpdate && systemctl start ntpdate       #  如果在启动ntp时报错，那是端口号被占用了，如下处理 

  [[email protected] ~]# yum install -y lsof

  [[email protected] ~]# lsof -i:123

  [[email protected] ~]# kill -9 $进程号

  [[email protected] ~]# systemctl enable ntpdate && systemctl start ntpdate

  [[email protected] ~]# crontab  -e

                      */5 * * * * /usr/sbin/ntpdate -u 202.120.2.101 && hwclock -w

二.安装，master && slave 一样

四、源码包安装

1、在三台安装依赖包

yum -y install gcc*

yum -y install readline-devel

2、在三台增加用户

# adduser postgres

 

3. 下载PostgreSQL 源码包

# wget https://ftp.postgresql.org/pub/source/v9.4.4/postgresql-9.4.4.tar.bz2    

4. 解压源码包

# tar xjf postgresql-9.4.4.tar.bz2      #需要安装     yum install -y bzip2  

5. 进入解压后的目录

# cd postgresql-9.4.4

6.开始编译安装PostgreSQL 数据库。

[[email protected] postgresql-9.4.4]# ./configure --prefix=/usr/local/pgsql

[[email protected] postgresql-9.4.4]#make

[[email protected] postgresql-9.4.4]# make install

7.设置环境

pgsql

[[email protected] postgres]# vi  /etc/profile

 PATH=$PATH:$HOME/bin:/usr/local/pgsql/bin

保存退出。

让环境变量生效

[[email protected] postgres]# source  /etc/profile

8.初始化数据库

8.1新建数据目录

[[email protected] postgres]# mkdir /data/pg/data

8.2更改权限

[[email protected] postgres]# chown postgres:postgres /data/pg/data

8.3切换到postgres用户

[[email protected] postgres]# su - postgres

8.4   init db

[[email protected] ~]$ /usr/local/pgsql/bin/initdb -D /data/pg/data

到这里数据的初始化就完成

9.系统服务

9.1回到root用户

[[email protected] ~]$ exit

9.2复制安装目录下的linux文件/etc/init.d/

进入postgresql的安装目录

[[email protected] postgres]# cd /root/postgresql-9.4.4/

[[email protected] postgresql-9.4.4]# cp contrib/start-scripts/linux /etc/init.d/postgresql

9.3修改/etc/init.d/postgresql  注意：红色是修改部分

[[email protected] postgresql-9.4.4]# vi /etc/init.d/postgresql

#! /bin/sh

 

# chkconfig: 2345 98 02

# description: PostgreSQL RDBMS

 

# This is an example of a start/stop script for SysV-style init, such

# as is used on Linux systems.  You should edit some of the variables

# and maybe the ‘echo‘ commands.

#

# Place this file at /etc/init.d/postgresql (or

# /etc/rc.d/init.d/postgresql) and make symlinks to

#   /etc/rc.d/rc0.d/K02postgresql

#   /etc/rc.d/rc1.d/K02postgresql

#   /etc/rc.d/rc2.d/K02postgresql

#   /etc/rc.d/rc3.d/S98postgresql

#   /etc/rc.d/rc4.d/S98postgresql

#   /etc/rc.d/rc5.d/S98postgresql

# Or, if you have chkconfig, simply:

# chkconfig --add postgresql

#

# Proper init scripts on Linux systems normally require setting lock

# and pid files under /var/run as well as reacting to network

# settings, so you should treat this with care.

 

# Original author:  Ryan Kirkpatrick <[email protected]>

 

# contrib/start-scripts/linux

 

## EDIT FROM HERE

 

# Installation prefix

prefix=/usr/local/pgsql

 

# Data directory

PGDATA="/data/pg/data"

# Who to run the postmaster as, usually "postgres".  (NOT "root")

PGUSER=postgres

 

# Where to keep a log file

PGLOG="$PGDATA/serverlog"

 

# It‘s often a good idea to protect the postmaster from being killed by the

# OOM killer (which will tend to preferentially kill the postmaster because

# of the way it accounts for shared memory).  Setting the OOM_SCORE_ADJ value

# to -1000 will disable OOM kill altogether.  If you enable this, you probably

# want to compile PostgreSQL with "-DLINUX_OOM_SCORE_ADJ=0", so that

# individual backends can still be killed by the OOM killer.

#OOM_SCORE_ADJ=-1000

# Older Linux kernels may not have /proc/self/oom_score_adj, but instead

# /proc/self/oom_adj, which works similarly except the disable value is -17.

# For such a system, enable this and compile with "-DLINUX_OOM_ADJ=0".

#OOM_ADJ=-17

 

## STOP EDITING HERE

 

# The path that is to be used for the script

PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

 

# What to use to start up the postmaster.  (If you want the script to wait

# until the server has started, you could use "pg_ctl start -w" here.

# But without -w, pg_ctl adds no value.)

DAEMON="$prefix/bin/postmaster"

 

# What to use to shut down the postmaster

PGCTL="$prefix/bin/pg_ctl"

 

set -e

 

# Only start if we can find the postmaster.

test -x $DAEMON ||

{

        echo "$DAEMON not found"

        if [ "$1" = "stop" ]

        then exit 0

        else exit 5

        fi

}

 

 

# Parse command line parameters.

case $1 in

  start)

        echo -n "Starting PostgreSQL: "

        test x"$OOM_SCORE_ADJ" != x && echo "$OOM_SCORE_ADJ" > /proc/self/oom_score_adj

        test x"$OOM_ADJ" != x && echo "$OOM_ADJ" > /proc/self/oom_adj

        su - $PGUSER -c "$DAEMON -D ‘$PGDATA‘ &" >>$PGLOG 2>&1

        echo "ok"

        ;;

  stop)

        echo -n "Stopping PostgreSQL: "

        su - $PGUSER -c "$PGCTL stop -D ‘$PGDATA‘ -s -m fast"

        echo "ok"

        ;;

  restart)

        echo -n "Restarting PostgreSQL: "

        su - $PGUSER -c "$PGCTL stop -D ‘$PGDATA‘ -s -m fast -w"

        test x"$OOM_SCORE_ADJ" != x && echo "$OOM_SCORE_ADJ" > /proc/self/oom_score_adj

        test x"$OOM_ADJ" != x && echo "$OOM_ADJ" > /proc/self/oom_adj

        su - $PGUSER -c "$DAEMON -D ‘$PGDATA‘ &" >>$PGLOG 2>&1

        echo "ok"

        ;;

  reload)

        echo -n "Reload PostgreSQL: "

        su - $PGUSER -c "$PGCTL reload -D ‘$PGDATA‘ -s"

        echo "ok"

        ;;

status)

        su - $PGUSER -c "$PGCTL status -D ‘$PGDATA‘"

        ;;

  *)

        # Print help

        echo "Usage: $0 {start|stop|restart|reload|status}" 1>&2

        exit 1

        ;;

esac

 

exit 0

 

9.4启动数据库

[[email protected] postgresql-9.4.4]#  cd /etc/init.d                                                              

[[email protected] postgresql-9.4.4]# chmod +x postgresql

[[email protected] postgresql-9.4.4]# /etc/init.d/postgresql start

9.5让数据库开机启动

[[email protected] postgresql-9.4.4]# chkconfig --add postgresql

[[email protected] postgresql-9.4.4]# chkconfig postgresql on

9.6创建数据操作历史记录文件

[[email protected] postgresql-9.4.4]# touch /usr/local/pgsql/.pgsql_history

[[email protected] postgresql-9.4.4]# chown postgres:postgres /usr/local/pgsql/.pgsql_history

10.测试使用

[[email protected] ~]$ createdb test

[[email protected] ~]$ psql test

psql (9.4.4)

Type "help" for help.

 

test=#

源码编译安装成功

这里安装以后要把数据库停掉，省的后面端口被占用后，配置改完了，重启不生效，楼主就是这个小问题导致试验了好几次都不成功，切记，装完把数据库停掉。

三.配置master

首先，在   vi pg_hba.conf

host    all             all             192.168.1.0/24          md5

host     replication     repluser        192.168.1.0/24          md5

其次，vi postgresql.conf

listen_addresses = ‘*‘

max_connections = 100

wal_level = hot_standby

max_wal_senders = 5

wal_keep_segments=16

在主库增加同步的用户名与密码

[[email protected] ~]$ psql -d postgres

psql (9.4.3)

Type "help" for help.

 

postgres=# CREATE ROLE repluser REPLICATION LOGIN PASSWORD ‘123456‘;

CREATE ROLE

postgres=#

启动master

四.配置standby

首先把数据库数据目录下的内容删除

cd /data/pg/data

rm -rf *

然后执行基础备份

[[email protected] data]# pg_basebackup -h 192.168.1.211 -U repluser -F p -x -P -R -D /data/pg/data/ -l repluserbackup20170913

执行完后，由于使用了R选项，所以会生成recovery.conf文件

vi  recovery.conf

standby_mode = ‘on‘

primary_conninfo = ‘user=repluser password=123456 host=192.168.1.211 port=5432 sslmode=disable sslcompression=1‘

recovery_target_timeline = ‘latest‘

vi postgresql.conf

hot_standby = on

启动standby

这里启动时要确保数据库之前没有启动，端口没被占用，这样修改的配置文件才会生效。切记

五.验证

在master上建个表，插入数据

postgres=# create table test01(id int primary key, note text);

postgres=# insert into test01 values(1,‘11111‘);

postgres=# insert into test01 values(3,‘22222‘);

postgres=# insert into test01 values(3,‘33333‘);

postgres=# insert into test01 values(4,‘44444‘);

postgres=# select * from test01;

 id | note  

----+-------

  1 | 11111

  2 | 22222

  3 | 33333

  4 | 44444

(4 rows)

postgres=# 

在slave上

postgres=# select * from test01;

 id | note  

----+-------

  1 | 11111

  2 | 22222

  3 | 33333

  4 | 44444

(4 rows)

还有一点就是，在master上执行

postgres=# select pg_is_in_recovery();

 pg_is_in_recovery 

-------------------

 f

(1 row)

而在slave上

postgres=# select pg_is_in_recovery();

 pg_is_in_recovery 

-------------------

 t

(1 row)

在master

postgres=# select client_addr,sync_state from pg_stat_replication;

  client_addr  | sync_state 

---------------+------------

 192.168.1.212 | async

(1 row)

说明94是从服务器，在接收流，而且是异步流复制。

此外，还可以分别在主、从节点上运行 ps aux | grep postgres 来查看进程：

主服务器（211）上：

[[email protected] ~]$ ps aux | grep postgres

postgres   1193  0.0  1.2 262720 13020 ?        S    16:56   0:00 /usr/local/pgsql/bin/postmaster -D /data/pg/data

postgres   1195  0.0  0.3 262820  3020 ?        Ss   16:56   0:00 postgres: checkpointer process                  

postgres   1196  0.0  0.2 262720  2228 ?        Ss   16:56   0:00 postgres: writer process                        

postgres   1197  0.0  0.5 262720  5192 ?        Ss   16:56   0:00 postgres: wal writer process                    

postgres   1198  0.0  0.1 263148  1788 ?        Ss   16:56   0:00 postgres: autovacuum launcher process           

postgres   1199  0.0  0.0 118012   988 ?        Ss   16:56   0:00 postgres: stats collector process               

postgres   1281  0.0  0.2 263352  2340 ?        Ss   17:31   0:00 postgres: wal sender process repluser 192.168.1.212(38215) streaming 0/30194E0

root       1414  0.0  0.1 145452  1608 pts/0    S    19:11   0:00 su - postgres

postgres   1415  0.0  0.1 108320  1884 pts/0    S    19:11   0:00 -bash

postgres   1445  0.0  0.1 110252  1172 pts/0    R+   19:19   0:00 ps aux

postgres   1446  0.0  0.0 103260   876 pts/0    S+   19:19   0:00 grep postgres

可以看到有一个 wal sender 进程。

从服务器（212）上：

[[email protected] ~]$ ps aux | grep postgres

postgres   1155  0.0  1.4 265236 14660 ?        S    17:31   0:00 /usr/local/pgsql/bin/postmaster -D /data/pg/data

postgres   1156  0.0  0.1 265336  1696 ?        Ss   17:31   0:00 postgres: startup process   recovering 000000010000000000000003

postgres   1157  0.0  0.2 265336  2520 ?        Ss   17:31   0:00 postgres: checkpointer process                  

postgres   1158  0.0  0.2 265236  2048 ?        Ss   17:31   0:00 postgres: writer process                        

postgres   1159  0.0  0.0 117860   900 ?        Ss   17:31   0:00 postgres: stats collector process               

postgres   1160  0.0  0.1 269764  1944 ?        Ss   17:31   0:03 postgres: wal receiver process   streaming 0/30194E0

root       1184  0.0  0.1 145452  1604 pts/0    S    17:49   0:00 su - postgres

postgres   1185  0.0  0.1 108320  1876 pts/0    S    17:49   0:00 -bash

postgres   1247  0.0  0.1 110252  1168 pts/0    R+   19:19   0:00 ps aux

postgres   1248  0.0  0.0 103260   876 pts/0    S+   19:19   0:00 grep postgres