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The first server1 in mysql Configuration file for 、 Execute command script 、 The compiled file is copied intact to server2 Under the same directory in .

stay server2 Create user , establish mysql The resource directory of , And specify everyone and all groups .

stay server2 Add mysql Environment variables of , and <source> Make it effective .

Yes server2 Medium mysqld Perform initialization operation

mysqld --initialize --user=mysql

After getting the initialization password , start-up mysql, And change the initialization password .

Two 、mysql Composition cluster of —— Configuration of the main server

1、 Official website information

2、 Set up mysql The server ID

stay </etc/my.cfg> Add two new lines to the file , The first line indicates the server name , The second line represents the server ID Number .

3、 restart mysql service

/etc/init.d/mysqld restart

Check the database status , It can be used normally. .

4、mysql All log files for

mysql All the log files are in </data/mysql> In the catalog <mysql-bin.000001> In file . It's an encrypted mysql Proprietary binaries , Special... Can be used <mysqlbinlog> Command view .

5、 Database internal operation —— to grant authorization

The first box indicates setting the password “westos”,“repl” Followed by the domain ,"%" Represents all domains .
The second box indicates authorization , “repl” Followed by the domain ,"%" Represents all domains , Therefore, it means that any host has access to .
The serial number of the third box indicates the log number of each change , The latest... Will be displayed .

CREATE USER 'repl'@'%' IDENTIFIED BY 'westos';
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';

3、 ... and 、mysql Composition cluster of —— Configuration from server

1、 Changing configuration files , Set from server ID by 2( In fact, just with 1 If it's different )

2、 Restart the database

3、 Set the master( To follow ) host

CHANGE MASTER TO 
MASTER_HOST='172.25.254.1',                 # Host to follow IP
MASTER_USER='repl',                         # The domain of the database in the host to follow 
MASTER_PASSWORD='westos',                   # The password of the database to follow 
MASTER_LOG_FILE='mysql-bin.000001',         # Log file of the database to follow 
MASTER_LOG_POS=595;                         # Oppress the following database logs ID( From this ID Start )

start slave;            # Start the following server

4、 Check the database status

show slave status\G ;

See these two lines “yes” It means from the server mysql Set up successfully . Listed parameters .

(4) test

stay server1 Create a new data table in the master server .

Change the contents of the data table ：

stay server2 in , Nothing moved , stay server1 The newly changed data in the master server will be automatically synchronized to server2 From the server .

Be careful ： This operation step is one-way , That is, on the primary server server1 Changes in are automatically synchronized to the slave server server2 in , Never be in server2 Change data in , Otherwise, the master and slave will not be synchronized . Therefore, it is generally from the server “ read-only ” Pattern .

Four 、 Basic principle of master-slave database

1、 Schematic diagram

2、 From the server server2 Data file information in

From the server server2 in , Data directory </data/mysql/> in , among <server2-relay-bin.index> Represents the log file <server2-relay-bin.000002> The index of .

<master.info> There is master Connection information of the host .

3、 Master-slave structure

There are two general master-slave structures , It is divided into “ One master, many followers ” and “ Linear one master one slave ”

“ Linear one master one slave ” Are the benefits of ,A After the update, you only need to synchronize the data to B, Don't look like “ One master, many followers ” Structure to synchronize data to B and C, master server A The pressure will be less .
“ One master, many followers ” The structure is suitable for “ Read more and write less ” The circumstances of .

5、 ... and 、 Build linearity “ Lord - from 1- from 2”

1、 build “ One master and two slaves ” structure —— Create a new slave server node server3

The data can be obtained from the previous server1 and server2 Directly copy the past

stay server3 In the following configuration ：

start-up mysql And change the password

2、 build “ Linear one master one slave ” structure —— From the server node server2 Configuration of

stay server2 Configuration file for </etc/my.cnf> Add the following two lines .

The first line is to start the binary log , To facilitate nodes server3 from server2 Synchronization information in ;
The second line is to start node log playback , That is to say server2 from server1 The data fetched in is played back to the binary log of the local machine .

When the changes are complete , restart server2 Of mysql service , You can see that

see server2 Log in <mysqlbinlog mysql-bin.000001 -v>, You can see in the server1 The changes just made in have been synchronized to server2 It's in .

The system only recognizes each synchronization <mysql-bin.000001> Log files , and <server2-relay-bin.index> What is recorded in the document is from server1 Synchronized record index in , The logs of all these records should be synchronized to <mysql-bin.000001> in .

3、mysql Data backup and recovery -------> Synchronization process

server1 The data backup ：

mysqldump -pwestos westos > dump.sql

In the actual production environment , Be sure to lock the watch . Because there is too much data , Backup takes time , If the table is not locked, new data will be written during the backup process, which will cause confusion in the backup data .

server3 Data recovery ：

Be careful ： Be careful of this pit . This sentence in the backup file means ： If... Exists in the current database “users” Words of watch , You have to delete it first .
intend , To keep the two databases consistent , Delete the original library first .
however , If the actual requirement is to merge two databases , The backed up data will directly overwrite the previous data . Cause loss to actual production .

Recovery process ：

Enter the first server3 In the database of , What also have no , either <westos> surface , So I created a <westos> surface .

Restore order ：

mysql -pwestos westos < dump.sql

server3 Synchronization settings for ：

First in server2 Add authorization to , You can see that the log sequence number is 1007,server3 To follow , Just set the serial number

CREATE USER 'repl'@'%' IDENTIFIED BY 'westos';
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';
flush privileges;                # Refresh database

And then in server3 Set in slave Following master server information , What we have to do here is “ Linear one master one slave ” structure , therefore server3 To follow is server2. After setting up , Still need to start slave！！！ Then check it out server3 Medium slave Information , Display succeeded .

CHANGE MASTER TO 
MASTER_HOST='172.25.254.2',                 # Host to follow IP
MASTER_USER='repl',                         # The domain of the database in the host to follow 
MASTER_PASSWORD='westos',                   # The password of the database to follow 
MASTER_LOG_FILE='mysql-bin.000001',         # Log file of the database to follow 
MASTER_LOG_POS=1007;                         # Oppress the following database logs ID( From this ID Start )

4、 test

stay server1 Change database in , stay server3 View in . You can see , The changes are synchronized to as soon as they are complete server3 in .

6、 ... and 、 build “ One master, many followers ” structure

1、 introduce GTID The concept of

Supplementary information ： One master and one slave , The master server will automatically find the slave server , therefore GTID No special configuration is required . One master and many slaves , When the primary server fails, it will look for the most “ near ” From the server , therefore GTID Manual configuration required .

GTID(Global Transaction Identifiers)—— Global transport identification

mysql The log of the server will be automatically added GTID Who should I look for next .

2、 build “ One master, many followers ” structure —— From the server node server2/3 Configuration of (GTID The way )

see master The state of ：

see slave state ：

Manual configuration GTID：

Manual configuration GTID when , need All master-slave nodes (server1/2/3) Add the following two lines to ; Indicates that the declaration is to use GTID Pattern , And force enable .

stay From the node server2 and server3 Set in mysql

change master to 
master_host='172.25.254.1',
master_user='repl', 
master_password='westos',
master_auto_position=1;                # Automatically update data

server2: