----配置同步流复制

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1.在主库增加同步的用户名与密码
****************************************************

$ psql -h 192.168.50.110  -d postgres -U postgres 
Password for user postgres: 
psql (9.4.4)
Type "help" for help.

postgres=# \l
                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges   
-----------+----------+----------+------------+------------+-----------------------
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
(3 rows)

postgres=# \c postgres
You are now connected to database "postgres" as user "postgres".

 
postgres=# SELECT rolname from pg_roles ;
 rolname  
----------
 postgres
 repluser
(2 rows)

postgres=# SELECT usename from pg_user; 
 usename  
----------
 postgres
 repluser
(2 rows)


postgres=# CREATE ROLE repluser REPLICATION LOGIN PASSWORD '123';
CREATE ROLE

postgres=#

****************************************************
2.新建测试数据库
****************************************************

postgres=# \l
                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges   
-----------+----------+----------+------------+------------+-----------------------
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
(3 rows)

postgres=# create database wind;
CREATE DATABASE
postgres=# \l
                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges   
-----------+----------+----------+------------+------------+-----------------------
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 wind      | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
(4 rows)

postgres=# \c wind;
You are now connected to database "wind" as user "postgres".
wind=# \d
No relations found.
wind=# create table t1(sid int not null primary key,sname varchar(10));
CREATE TABLE
wind=# insert into t1 values(101,'ocpyang');
INSERT 0 1
wind=# insert into t1 values(102,'yzw');
INSERT 0 1
wind=# select * from t1;
 sid |  sname  
-----+---------
 101 | ocpyang
 102 | yzw
(2 rows)



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3.在主库pg01上进行配置
****************************************************

--3.1
$ vi /data/pg/data/pg_hba.conf
增加以下：
host    replication     repluser        192.168.50.0/24           md5


--3.2 在主库pg01的/data/pg/data/postgresql.conf中设置如下三个参数
$ vi /data/pg/data/postgresql.conf
 
59  listen_addresses = '*'
175 wal_level = hot_standby
224 max_wal_senders = 5 
226 wal_keep_segments = 64  




--3.3 在主数据上指定同步复制的Standby名称，在主库pg01的/data/pg/data/postgresql.conf中设置:
vi /data/pg/data/postgresql.conf
 
236 synchronous_standby_names = 'pg02'


--3.4 修改上述参数后需要重启数据库.

pg_ctl -m "immediate" restart


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4.在备库pg02上进行配置
****************************************************

$pg_ctl -m "immediate" stop 

-----4.1 备份数据

$rm -rf /data/pg/data/*

$pg_basebackup -h 192.168.50.110 -U repluser -F p -P -x -R -D /data/pg/data/ -l backup20150921
Password: 
54491/54491 kB (100%),1/1 tablespace

--4.2 修改备库的pg02的recovery.conf 

$ cat /data/pg/data/recovery.conf 
standby_mode = 'on'
primary_conninfo = 'user=repluser password=123 host=192.168.50.110 port=5432 sslmode=disable sslcompression=1'


$vi /data/pg/data/recovery.conf 

#增加application_name,这个参数和主库中synchronous_standby_names指定的对应值一样.
standby_mode = 'on'
primary_conninfo = 'application_name=pg02 user=repluser password=123 host=192.168.50.110 port=5432 sslmode=disable sslcompression=1'
recovery_target_timeline = 'latest' # 这个说明这个流复制同步到最新的数据


---4.3 修改备库的pg02的postgresql.conf 

vi /data/pg/data/postgresql.conf 

64 max_connections = 1000 ＃ 一般查多于写的应用从库的最大连接数要比较大
245 hot_standby = on 
255 hot_standby_Feedback = on  


---4.4 备库pg02启动

pg_ctl  start


$ cat  /data/pg/data/pg_log/pg01-2015-09-21_151458.log 
LOG:  database system was shut down in recovery at 2015-09-21 15:14:29 CST
LOG:  entering standby mode
LOG:  redo starts at 0/30002E8
LOG:  consistent recovery state reached at 0/30003C0
LOG:  database system is ready to accept read only connections
LOG:  record with zero length at 0/30003C0
LOG:  started streaming WAL from primary at 0/3000000 on timeline 1


****************************************************
5.复制监控
****************************************************

select pid,state,client_addr,sync_priority,sync_state from pg_stat_replication;

 pid  |   state   |  client_addr   | sync_priority | sync_state 
-------+-----------+----------------+---------------+------------
 65392 | streaming | 192.168.50.120 |             1 | sync
(1 row)


+-----+----------+----------+------------------+----------------+-----------------+-------------+-------------------------------+--------------+-----------+---------------+----------------+----------------+-----------------+---------------+------------+
| pid | usesysid | usename  | application_name | client_addr    | client_hostname | client_port | backend_start                 | backend_xmin | state     | sent_location | write_location | flush_location | replay_location | sync_priority | sync_state |
+-----+----------+----------+------------------+----------------+-----------------+-------------+-------------------------------+--------------+-----------+---------------+----------------+----------------+-----------------+---------------+------------+
| 632 | 16384    | repluser | pg02             | 192.168.50.120 | NULL            |       36746 | 2015-09-21 17:17:41.730857+08 | 1826         | streaming | 0/3002718     | 0/3002718      | 0/3002718      | 0/3002718       |             1 | sync       |
+-----+----------+----------+------------------+----------------+-----------------+-------------+-------------------------------+--------------+-----------+---------------+----------------+----------------+-----------------+---------------+------------+
1 row in set




pid              | 8467       # sender的进程
usesysid         | 44673      # 复制的用户id
usename          | replica    # 复制的用户用户名
application_name | walreceiver  
client_addr      | 10.12.12.12 # 复制的客户端地址
client_hostname  |
client_port      | 55804  # 复制的客户端端口
backend_start    | 2015-05-12 07:31:16.972157+08  # 这个主从搭建的时间
backend_xmin     |
state            | streaming  # 同步状态 startup: 连接中、catchup: 同步中、streaming: 同步
sent_location    | 3/CF123560 # Master传送WAL的位置
write_location   | 3/CF123560 # Slave接收WAL的位置
flush_location   | 3/CF123560 # Slave同步到磁盘的WAL位置
replay_location  | 3/CF123560 # Slave同步到数据库的WAL位置
sync_priority    | 0  #同步Replication的优先度
                      0: 异步、1～?: 同步(数字越小优先度越高)
sync_state       | async  # 有三个值，async: 异步、sync: 同步、potential: 虽然现在是异步模式，但是有可能升级到同步模式