MySQL主從同步原理和部署

一.主從的做用：

1.能夠當作一種備份方式

2.用來實現讀寫分離，緩解一個數據庫的壓力

二.MySQL主從備份原理

master  上提供binlog ,

slave    通過 I/O線程從 master拿取 binlog,並復制到slave的中繼日誌中

slave    通過 SQL線程從 slave的中繼日誌中讀取binlog ,然後解析到slave中

部署主從環境：主服務器：192.168.1.110（編譯好的MySQL5.1版本的數據庫）

從服務器：192.168.1.120（編譯好的MySQL5.1版本的數據庫）

（溫馨提示：主和從數據庫版本必須是一樣。或者主庫的數據庫版本必須比從庫高,否則會導致不少故障的發生。）

三：生產環境應用MySQL主從同步場景：

1. 通常用主庫作為提供業務用戶寫操做（好比：在互聯網上寫一條微博，這時候就會寫到mysql數據庫的主庫中）

2. 通常用從庫作為提供業務用戶讀操做（好比：在互聯網上，我想看一條微博，這時候裏面提供數據就是MySQL數據庫的從庫中。）

(1)在主服務器（192.168.1.110）上操做。

[root@Andy  ~]# ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:0C:29:5E:6F:A7

inet addr:192.168.1.110  Bcast:192.168.1.255  Mask:255.255.255.0

inet6 addr: fe80::20c:29ff:fe5e:6fa7/64 Scope:Link

UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

RX packets:141354 errors:0 dropped:0 overruns:0 frame:0

TX packets:140807 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:142083379 (135.5 MiB)  TX bytes:17815696 (16.9 MiB)

Interrupt:193 Base address:0x2000

[root@Andy  ~]# vi /etc/my.cnf

[mysqld]在mysqld下添加以上兩行。

server-id = 1

log-bin= Andy -bin

[root@Andy  ~]# /etc/init.d/mysqld restart

Shutting down MySQL[  OK  ]

Starting MySQL.[  OK  ]

[root@Andy ~]# mysql

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 4

Server version: 5.1.44 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show master status;

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

| File               | Position | Binlog_Do_DB | Binlog_Ignore_DB |

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

|  Andy-bin.000001 |      106 |              |                  |

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

1 row in set (0.00 sec)

請記住：File裏的Andy-bin.000001 和 Position 106 。

Mysql> grant replication slave on *.* to 'python'@'192.168.1.%' identified by '123456';

mysql> quit

Bye

在從服務器（192.168.1.120）上操做：

[root@Andy  ~]# ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:0C:29:2B:8E:D2

inet addr:192.168.1.120  Bcast:192.168.1.255  Mask:255.255.255.0

inet6 addr: fe80::20c:29ff:fe2b:8ed2/64 Scope:Link

UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

RX packets:180290 errors:0 dropped:0 overruns:0 frame:0

TX packets:146169 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:223411069 (213.0 MiB)  TX bytes:15504427 (14.7 MiB)

Interrupt:193 Base address:0x2000

[root@Andy  ~]# vi /etc/my.cnf

把server-id       = 1 改為：server-id       = 2

然後重啟Mysql服務：[root@Andy  ~]# /etc/init.d/mysqld restart

Shutting down MySQL........[  OK  ]

Starting MySQL.[  OK  ]

[root@Andy  ~]# mysql

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 1

Server version: 5.1.44 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> CHANGE MASTER TO MASTER_HOST='192.168.1.110', MASTER_PORT=3306, MASTER_USER='python', MASTER_PASSWORD='123456', MASTER_LOG_FILE='  Andy-bin .000001', MASTER_LOG_POS=106;

mysql> start slave;

Query OK, 0 rows affected (0.00 sec)

mysql> show slave status\G

*************************** 1. row ***************************

Slave_IO_State: Waiting for master to send event

Master_Host: 192.168.1.110

Master_User: python

Master_Port: 3306

Connect_Retry: 60

Master_Log_File:  Andy-bin.000001

Read_Master_Log_Pos: 106

Relay_Log_File:  Andy-relay-bin.000002

Relay_Log_Pos: 253

Relay_Master_Log_File:  Andy-bin.000001

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

Replicate_Do_DB:

Replicate_Ignore_DB:

Replicate_Do_Table:

Replicate_Ignore_Table:

Replicate_Wild_Do_Table:

Replicate_Wild_Ignore_Table:

Last_Errno: 0

Last_Error:

Skip_Counter: 0

Exec_Master_Log_Pos: 106

Relay_Log_Space: 410

Until_Condition: None

Until_Log_File:

Until_Log_Pos: 0

Master_SSL_Allowed: No

Master_SSL_CA_File:

Master_SSL_CA_Path:

Master_SSL_Cert:

Master_SSL_Cipher:

Master_SSL_Key:

Seconds_Behind_Master: 0

Master_SSL_Verify_Server_Cert: No

Last_IO_Errno: 0

Last_IO_Error:

Last_SQL_Errno: 0

Last_SQL_Error:

1 row in set (0.01 sec)

若是：    Slave_IO_Running: Yes （主從I/O正確）

Slave_SQL_Running: Yes（主從進程正確）

（3）測試主從數據同步：在主服務器（192.168.1.110）上操做：

[root@Andy ~]# ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:0C:29:5E:6F:A7

inet addr:192.168.1.110  Bcast:192.168.1.255  Mask:255.255.255.0

inet6 addr: fe80::20c:29ff:fe5e:6fa7/64 Scope:Link

UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

RX packets:142562 errors:0 dropped:0 overruns:0 frame:0

TX packets:141697 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:142192520 (135.6 MiB)  TX bytes:17915582 (17.0 MiB)

Interrupt:193 Base address:0x2000

[root@Andy  ~]# mysql

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3

Server version: 5.1.44-log Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> create database Andy ;

Query OK, 1 row affected (0.00 sec)

mysql> show databases;

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

| Database           |

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

| information_schema |

| Andy                 |

| mysql              |

| test               |

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

4 rows in set (0.00 sec)

mysql> use  Andy ;

Database changed

mysql> create table  Andy (id int(3),name char(10));

Query OK, 0 rows affected (0.01 sec)

mysql> insert into  Andy  values (001,'imysql');

Query OK, 1 row affected (0.00 sec)

(提示：我剛剛在主服務器上創建了一個Andy 數據庫和表，我現在在從服務器上查看結果，是否有Andy數據庫和表？)

在從服務器（192.168.1.120）上操做：

[root@Andy   ~]# ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:0C:29:2B:8E:D2

inet addr:192.168.1.120  Bcast:192.168.1.255  Mask:255.255.255.0

inet6 addr: fe80::20c:29ff:fe2b:8ed2/64 Scope:Link

UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

RX packets:180884 errors:0 dropped:0 overruns:0 frame:0

TX packets:146585 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:223461833 (213.1 MiB)  TX bytes:15555296 (14.8 MiB)

Interrupt:193 Base address:0x2000

[root@Andy   ~]# mysql

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 4

Server version: 5.1.44 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;

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

| Database           |

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

| information_schema |

| Andy                 |

| mysql              |

| test               |

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

4 rows in set (0.00 sec)

mysql> use  Andy ;

Database changed

mysql> select * from  Andy ;

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

| id   | name   |

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

|    1 | imysql |

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

1 row in set (0.00 sec)