Postgresql standby(备机只读)环境搭建

PostgreSQL · suifu · 于 11个月前发布 · 461 次阅读
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/postgres@192.168.5.252:/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

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