Postgresql standby（备机只读）环境搭建

下载PostgreSQL源码包，放在任意目录

设置/etc/sysctl.conf,增加以下内容

kernel.shmmni= 4096

kernel.sem =501000 6412800000 501000 12800

fs.file-max =767246

net.ipv4.ip_local_port_range= 1024 65000

net.core.rmem_default= 1048576

net.core.rmem_max= 1048576

net.core.wmem_default= 262144

net.core.wmem_max= 262144

net.ipv4.tcp_tw_recycle=1

net.ipv4.tcp_max_syn_backlog=4096

net.core.netdev_max_backlog=10000

vm.overcommit_memory=0

net.ipv4.ip_conntrack_max=655360

sysctl -p 生效

如果这里出现最后一个参数未生效可：

modprobeip_conntrack

echo"modprobe ip_conntrack" >> /etc/rc.local

 设置/etc/security/limits.conf 增加以下内容

* soft    nofile  131072

* hard    nofile  131072

* soft    nproc   131072

* hard    nproc   131072

* soft    core    unlimited

* hard    core    unlimited

* soft    memlock 50000000

* hard    memlock 50000000

--vi/etc/pam.d/login

sessionrequired pam_limits.so

设置环境变量

#vi .bash_profile 在文件尾添加 

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

exportMANPATH=$MANPATH:/usr/local/pgsql/man

exportLD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/pgsql/lib

export PGDATA=/opt/pgdata

先修改好两台机器的名称

[root@primary ~]# groupadd postgres

[root@primary ~]# useradd -g postgres postgres

[root@primary ~]# passwd postgres

[postgres@primary~]$ tar -zxvf postgresql-9.3.0.tar.gz

[postgres@primary~]$ cd postgresql-9.3.0

[postgres@primary postgresql-9.3.0]$ ./configure --prefix /home/proxy_pg/pgsql  #配置安装目录

[postgres@primary postgresql-9.3.0]$ make   #这里需要安装基础的库(gcc、readline、zlib、) 可以不必理会，make时会提示

[root@primary ~]# mkdir /home/proxy_pg

[root@primary ~]# chown -R postgres /home/proxy_pg

[postgres@primary postgresql-9.3.0]$ make install#安装

[postgres@primary pgsql]$ mkdir /home/proxy_pg/pgsql/data        #在你想要存放数据的地方创建data文件夹

[postgres@primary bin]$ ./initdb -D ../data/             #初始化数据库

[postgres@primarydata]$ vi postgresql.conf    #修改data/postgresql.conf

port = 5432                        #可以任意更改你想要的,这里直接用5432

wal_level = hot_standby       #主库设置成 hot_standby ，从库才能以READ-ONLY模式打开

max_wal_senders = 30        #WAL STREAM 日志发送进程数

log_connections = on              #设置日志参数，记录连接信息

logging_collector = on                #开启csvlog输出功能(默认为off)

log_directory = ‘pg_log‘        #设置csv日志输出目录($PGDATA目录下，如果不存在该目录，则会自动新建)

log_destination = ‘csvlog‘   #设置输出的日志式(类型)，pg中的日志类型有stderr、csvlog、syslog以及eventlog，本例中设置为csvlog

#该选项默认为stderr类型

archive_mode= on

archive_command = ‘test ! -f /archive/pg93/archive_active || cp %p/archive/pg93/%f‘ #备注：归档标识文件 archive_active  需要手工创建。

wal_keep_segments = 1024      #主库设置的 wal_keep_segments 参数为 1024，一个较大的 wal_keep_segments 设置，允许

            备库在宕机较长的时间内依然能够重新追上主库，当然这与主库的繁忙程度有关，主库越忙，

           产生的 WAL 日志越多，之前的 WAL 日志越容易被覆盖，进而出现FATAL,XX000错误。

注：修改完logging_collector后需要重启数据库(当然你也可以继续配置，在所有配置都完成后再重启)

[root@primary   ~]#mkdir -p /archive/pg93   

[root@primary ~]# chown -R postgres /archive

[root@primary ~]# cd /archive/pg93/

[root@primary pg93]#touch archive_active

以上操作备库也执行

修改data/pg_hba.conf

 host   replication     postgres        192.168.5.0/24          trust

 启动主数据库bin/pg_ctl start -D ../data/

[postgres@primarybin]$ ./pg_ctl start -D ../data

检测数据库是否启动成功

[postgres@primarybin]$ ./psql -d postgres

psql(9.3.0)

Type"help" for help.

postgres=#         #说明启动成功了

 基础备份

基本流程：在主数据库服务器上执行pg_start_backup(),复制data目录，在执行pg_stop_backup()。

./psql–d postgres

postgres=#select pg_start_backup(‘base backup for logstreaming‘);

#使用这个方法后，所有请求在写日志之后不会再刷新到磁盘。直到执行pg_stop_backup()这个函数。

#下面需要拷贝一份data目录，并通过scp复制到子数据库中

[postgres@primarypgsql]$ cp -r data data_bak

创建从数据库(standby)

#通过scp方式拷贝data_bac目录到从数据库下(当然也可以通过其他方式)

[postgres@primarypgsql]$ scp -r data_bak/[email protected]:/home/proxy_pg/pgsql/

#进入从数据库服务器，进入刚刚拷贝过来的data_bac目录下

[postgres@standby~]$ cd /home/proxy_pg/pgsql/data_bak

#修改postgres.conf

port = 5432 #改成你想的端口

hot_standby = on    #从库上可以执行只读操作

 log_connections = on

copy完后，停止主数据库基础备份

postgres=#select pg_stop_backup();

#增加recovery.conf配置下连接的主数据库信息(ip、端口、用户)

[postgres@standby share]$ cp recovery.conf.sample ../data/recovery.conf     #可以从share中拷贝一份模板

[postgres@standbydata_bak]$ vi recovery.conf

standby_mode= ‘on‘

primary_conninfo= ‘host=192.168.5.248 port=5432 user=postgres‘

trigger_file = ‘/tmp/postgresql.trigger.5432‘

#删除pid文件

[postgres@standbydata_bak]$ rm -f postmaster.pid

启动从数据库，并观察CSVLOG

bin/pg_ctl start -D ../data_bak/

 观察CSVLOG

[postgres@primarypg_log]$ tail -f postgresql-2014-10-28_155549.csv

2014-10-2815:55:49.522 GMT-8,,,27977,,544f4c05.6d49,1,,2014-10-28 15:55:49GMT-8,,0,LOG,00000,"ending log output to stderr",,"Future logoutput will go to log destination""csvlog"".",,,,,,,""

2014-10-2815:55:49.523 GMT-8,,,27979,,544f4c05.6d4b,1,,2014-10-28 15:55:49GMT-8,,0,LOG,00000,"database system was shut down at 2014-10-28 15:33:33GMT-8",,,,,,,,,""

2014-10-2815:55:49.612 GMT-8,,,27977,,544f4c05.6d49,2,,2014-10-28 15:55:49GMT-8,,0,LOG,00000,"database system is ready to acceptconnections",,,,,,,,,""

2014-10-2815:55:49.612 GMT-8,,,27983,,544f4c05.6d4f,1,,2014-10-28 15:55:49GMT-8,,0,LOG,00000,"autovacuum launcher started",,,,,,,,,""

2014-10-2815:56:34.436 GMT-8,,,28048,"",544f4c32.6d90,1,"",2014-10-2815:56:34 GMT-8,,0,LOG,00000,"connection received:host=[local]",,,,,,,,,""

2014-10-2815:56:34.437GMT-8,"postgres","postgres",28048,"[local]",544f4c32.6d90,2,"authentication",2014-10-2815:56:34 GMT-8,2/1,0,LOG,00000,"connection authorized: user=postgresdatabase=postgres",,,,,,,,,""

2014-10-2816:06:14.597 GMT-8,,,28199,"",544f4e76.6e27,1,"",2014-10-2816:06:14 GMT-8,,0,LOG,00000,"connection received: host=192.168.5.252port=49654",,,,,,,,,""

2014-10-2816:06:14.598GMT-8,"postgres","",28199,"192.168.5.252:49654",544f4e76.6e27,2,"authentication",2014-10-2816:06:14 GMT-8,3/21,0,LOG,00000,"replication connection authorized:user=postgres",,,,,,,,,""

2014-10-2816:11:29.501 GMT-8,,,28251,"",544f4fb1.6e5b,1,"",2014-10-2816:11:29 GMT-8,,0,LOG,00000,"connection received: host=192.168.5.252port=50285",,,,,,,,,""

2014-10-2816:11:29.502GMT-8,"postgres","",28251,"192.168.5.252:50285",544f4fb1.6e5b,2,"authentication",2014-10-2816:11:29 GMT-8,3/28,0,LOG,00000,"replication connection authorized:user=postgres",,,,,,,,,""

这些信息说明流复制已经成功，从库正准备接收主库的WAL-STREAM。

主库观察WAL-Sender进程 

[postgres@primarybin]$ ps -ef |grep post

postgres 2825127977  0 16:11 ?        00:00:00 postgres: wal sender processpostgres 192.168.5.252(50285) streaming 0/60009A8

说明：将输出结果省略部分，可以看到 " wal sender process repuser"进程

 在从库上观察 WAL-接收进程

[postgres@standbydata_bak]$ ps -ef |grep post

postgres 1191611911  0 16:11 ?        00:00:00 postgres: wal receiverprocess   streaming 0/60009A8

说明：同样省略部分输出结果，可以看到“ wal receiver process ” 进程。

测试

主库上创建用户

postgres=# CREATE ROLE browser LOGIN ENCRYPTED PASSWORD ‘browser‘

postgres-# nosuperuser noinherit nocreatedb nocreateroleCONNECTION LIMIT 200;

CREATE ROLE

从库上验证

postgres=# \du

                             List of roles

 Role name |                   Attributes                   | Member of

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

 browser  | No inheritance                                +| {}

           | 200 connections                                |

 postgres | Superuser, Create role, Create DB, Replication | {}

说明：果然，在从库上就立刻创建了新用户 ‘browser‘

主库上创建表空间(On Master)

[postgres@primarydata]$ mkdir -p/home/proxy_pg/pgsql/data/pg_tbs/tbs_browser

从库上也执行 mkdir -p  (On  Sandby)

[postgres@standbydata_bak]$  mkdir -p /home/proxy_pg/pgsql/data/pg_tbs/tbs_browser

主库上

postgres=# create tablespace tbs_browser owner browser LOCATION

postgres-# ‘/home/proxy_pg/pgsql/data/pg_tbs/tbs_browser‘;

CREATE TABLESPACE

--在从库上验证

postgres=# \db

                          List of tablespaces

    Name    |  Owner   |                   Location                  

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

 pg_default | postgres |

 pg_global  | postgres |

 tbs_browser | browser  |/home/proxy_pg/pgsql/data/pg_tbs/tbs_browser

(3 rows)

表空间"tbs_browser" 也立刻创建过来了

主库上创建数据库

postgres=# CREATE DATABASE browser WITH OWNER = browser TEMPLATE= template0 ENCODING = ‘UTF8‘ TABLESPACE = tbs_browser;

CREATE DATABASE

--从库上验证

postgres=# \l

                                  List ofdatabases

   Name   |  Owner   | Encoding |   Collate  |    Ctype    |  Access privileges  

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

 browser  | browser  | UTF8     | zh_CN.UTF-8 | zh_CN.UTF-8 |

 postgres | postgres | UTF8     |zh_CN.UTF-8 | zh_CN.UTF-8 |

 template0 | postgres | UTF8     | zh_CN.UTF-8 | zh_CN.UTF-8 |=c/postgres          +

           |          |          |             |             | postgres=CTc/postgres

 template1 | postgres | UTF8     | zh_CN.UTF-8 | zh_CN.UTF-8 |=c/postgres          +

           |          |          |             |             | postgres=CTc/postgres

(4 rows)

从库上数据库 "browser" 也立刻有了，几乎没有延时。

 在从库上建表

postgres=# create table table3(id integer);

ERROR:  cannot execute CREATE TABLE in a read-onlytransaction

说明：从库是以只读形式打开，只能执行读操作，不能写。

监控streaming

postgres=# select * from pg_stat_replication ;

  pid  |usesysid | usename  | application_name|  client_addr  | client_hostname | client_port |         backend_start         |  state   | sent_location

| write_location |flush_location | replay_location | sync_priority | sync_state

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

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

 28251 |      10 | postgres | walreceiver      |192.168.5.252 |                 |       50285 | 2014-10-28 16:11:29.501421+08 |streaming | 0/6001C70    

| 0/6001C70      | 0/6001C70      | 0/6001C70       |             0 | async

(1 row)

本文出自 “岁伏” 博客，请务必保留此出处http://suifu.blog.51cto.com/9167728/1575880