Implementation of MySQL master-slave architecture

Catalog

• 1.   Environmental preparation ：
  2.   Preparation steps ：
  3.   Implementation steps :
     1.   To configure master master server
     2.   Create a copy account
     3.   Check the main server status
     4.   To configure slave From the server
     5.   Start the copy thread from the server
     6.   View the status of the slave server
     7.   test
  4.   Expand —— Realize one master and many slaves
     1.   Demand analysis
     2.   Specific implementation process
  5.   Expand —— Realize semi synchronous replication
     1.   Three ways to copy
     2.   Realize semi synchronous replication
• 1.   Environmental preparation ：
  2.   Preparation steps ：
  3.   Implementation steps ：
     1.   Configure the first master master server
     2.   Configure the second master master server
     3.   Create a copy account
     4.   View server status
     5.   Start replication thread
     6.   test
• MHA The implementation of the

 

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A master from

1.1 Environmental preparation ：

centos System server 2 platform 、 One user does Mysql master server , One for Mysql From the server , Good configuration yum Source 、 Firewall OFF 、 The clock service of each node is synchronized 、 Nodes can communicate with each other through host names

1.2 Preparation steps ：

1）iptables -F && setenforce Clear firewall policy , close selinux

2） Use both servers yum Way to install Mysql service , The version is required to be consistent

3） Start two servers respectively mysql service , Make sure the service is normal

　　 Architecture diagram :

 

1.3 Implementation steps :

1.3.1 To configure master master server

Yes master To configure , Including opening binary logs , Assign a unique servr ID. for example , Add the following values to the configuration file [mysqld]

# open Mysql journal , The log format is binary

log-bin=/usr/local/mysql/data/binlog/mysql-bin

#[ must ] The server is unique ID, The default is 1

server-id=1

# Every write is synchronized with the hard disk

sync-binlog=1

# The name of the binary database to be synchronized

binlog-do-db=tuling

# Only keep 7 Days of binary logs , In case the disk is full of logs

expire-logs-days  = 7

# Database not backed up

binlog-ignore-db=information_schema

binlog-ignore-db=performation_schema

binlog-ignore-db=sys

skip-name-resolve　　

// Turn off name resolution ,（ Not necessary ）

 

1.3.2 Create a copy account

　　 stay Master In the database of Backup account (user = tuling,pwd=root)： Every slave standards-of-use MySQL User name and password connection master . The user who makes the copy will grant REPLICATION SLAVE jurisdiction .

# Create user MariaDB [(none)]> CREATE USER 'tuling'@'192.168.%.%' IDENTIFIED BY 'root'; # to grant authorization MariaDB [(none)]> grant replication slave,replication client on *.* to tuling@'192.168.%.%' identified by 'root'; # Refresh the permissions MariaDB [(none)]> FLUSH PRIVILEGES;

1.3.3 Check the main server status

　　 stay Master Database execution  show master status, View the binary log status and location number of the primary server .

 

1.3.4 To configure slave From the server

　　 Yes slave To configure , Turn on the relay log , Assign a unique servr ID, Set read-only permissions . Add the following values to the configuration file ：

    server-id=2                 // To configure server-id, Let the slave server have a unique ID Number    

relay_log = mysql-relay-bin // open Mysql relay journal , The log format is binary    

read_only = 1               // Set read-only permissions    

log_bin = mysql-bin         // Turn on the binary log from the server    

log_slave_updates = 1       // Make the updated data written in the binary log    

# If salve Library name and master The library name is the same , Use this configuration    

replicate-do-db = tuling    # If master Library name [tuling] And salve Library name [tuling01] Different , Use the following configuration [ You need to map ]    

replicate-rewrite-db = tuling[ Main database name ] -> tuling01[ From the library name ]    # If you don't want to synchronize them all [ By default, synchronize all ], Then specify the tables that need to be synchronized    

replicate-wild-do-table=tuling01.t_order    

replicate-wild-do-table=tuling01.t_order_item

 

1.3.5 Start the copy thread from the server

　　 Give Way slave Connect master , And start doing it again master Events in binary logs .

MariaDB [(none)]> change master to master_host='192.168.241.198', [ Yours master-ip]   >master_user='tuling',    

>master_password='root',    

>master_log_file='mysql-bin.000007', //master Corresponding bin-log file  

>master_log_pos=413; //master Corresponding position      

>start slave; // Start replication thread .     

>SHOW SLAVE STATUS\G; // View the slave node status      # Error may be reported during startup ：   ERROR 3021 (HY000): This operation cannot be performed with a running slave io thread;run STOP SLAVE IO_THREAD FOR CHANNEL '' first.   

# terms of settlement   

// When setting the synchronization relationship , It didn't stop first slaves Threads . The solution is before setting up the synchronization relationship ,   

// Execute first “stop slave;”, To stop slave Threads . Then start the thread "start slave;"

1.3.6 View the status of the slave server

　　 You can use SHOW SLAVE STATUS\G; View the status of the slave server , As shown below , Also available show processlist \G; View the current replication status ：

    Slave_IO_Running: Yes       //IO The thread is running normally     Slave_SQL_Running: Yes      //SQL The thread is running normally

 

1.3.7 test

1） Test master-slave synchronization

　　 We are master Create a database on the server , Then use the database to create a table , Add a record , Take a look at slave Does the server synchronize successfully .

　　 First , Let's take a look at the databases on the two servers ：

master：

 

slave：

 

　　 Now? , We create a database on the primary server “keer”：

 

　　 then , Let's see if the slave server has been updated ：

 

　　 We can see that , The database has been synchronized , Next , Let's create the table , And insert a record in the table ：

 

　　 then , Let's see if the slave server is updated ：

 

2） Test read-only properties

　　 We set read-only on the slave server , So let's try to insert data ：

 

　　 This is awkward , Why do we set read-only or insert data ？ How can this be solved ？

　　 Because when we log in, we use root The super user , This big perversion is not affected by the read-only setting , therefore , We can still insert data into it , Of course , If we switch to other ordinary users, we won't have such a problem .

　　 The solution is simple , We just need to lock the watch ：

MariaDB [keer]> flush tables with read lock;

　　 After locking the table , Let's insert another piece of data ：

 

　　 In this case , Even if we log in as super users , No more data can be inserted . It's a lot safer . however , There are advantages and disadvantages , In this case , Our master and slave cannot synchronize in real time , Because our master-slave synchronization is through the master-slave synchronization sql The statement is implemented by executing it again from the top , But if we lock the watch ,sql Statement cannot be executed . It is also easy to synchronize , Just unlock the table .

　　 We insert a piece of data on the master ：

 

　　 here , From the top, we need to solve the table before we can realize synchronization ：

 

1.4 Expand —— Realize one master and many slaves

1.4.1 Demand analysis

　　 When our server runs for a while , Traffic is getting more and more , At this time , The high availability and load balancing that one master and one slave can achieve cannot meet our needs , We will choose to add another slave server .

　　 But now our master It's been running for a long time , We also need to check the new installation slave Data synchronization , Even it doesn't have master The data of .

　　 here , There are several ways to make slave Start with another service , for example , from master Copy the data , From the other slave clone , Start with the most recent backup slave . In order to speed up slave And master Sync , Data synchronization can be carried out first in the following ways ：

（1）master A snapshot of the data at some point in time ;

（2） Backup data of database ;

（3）master Binary log file of .

　　 Next , Let's implement this process ：

1.4.2 Specific implementation process

1） Yes master Make a full backup

[[email protected] ~]# mkdir /backup [[email protected] ~]# mysqldump --all-database > /backup/mysql-backup-`date +%F-%T`-all.sql

Check the binary log status and location number of the master as usual .

 

2） Send the fully backed up data to the newly added slave

[[email protected] ~]# scp /backup/mysql-backup-2017-11-21-10\:28\:29-all.sql @192.168.37.133:~ [email protected]'s password: mysql-backup-2017-11-21-10:28:29-all.sql                                                           100%  504KB 503.9KB/s   00:00

3） Import this full backup into the database from ：

 

4） Check whether the recovery from is successful ：

 

 

　　 Let's check the binary log status and location number of the slave ：

 

　　 Our data has been recovered successfully

5） Set up master and slave

The next step is to follow the above steps , Set the slave server ：

[[email protected] ~]# vim /etc/my.cnf    [mysqld]    server-id = 3    relay-log = mysql-relay-bin    read-only = 1    log-bin = mysql-bin    log-slave-updates = 1

　　 then , Let's set up the slave server ：

[[email protected] ~]# mysql -uroot -p Enter password: MariaDB [(none)]> change master to master_host='192.168.37.111',    >master_user='slave',    >master_password='keer',    >master_log_file='mysql-bin.000001',    >master_log_pos=330; MariaDB [(none)]> start slave;

　　 Then let's check the status of the slave server ：

 

6） test

　　 Setup complete , So let's test that out , When the master has operations , Whether to update from ：

 

 

　　 thus , We have completed one master and two slaves . If necessary , We can also continue to add slave servers .

1.5 Expand —— Realize semi synchronous replication

1.5.1 Three ways to copy

1） Synchronous replication

　　 When the master library completes a transaction , All slave libraries execute the transaction To the client . Because you need to wait for all the transactions from the library to complete before returning , So full synchronous replication Performance is bound to be severely affected . Need a timeout .

2） Asynchronous replication

MySQL The default copy That is, asynchronous , The main database will return the result to the client immediately after executing the transaction submitted by the client , It doesn't matter if the slave library has been received and processed , There will be a problem , Lord if crash It fell off , At this time, the submitted transactions on the master may not be transferred to the slave , If at this time , Force will come first from ascension , May result in incomplete data on the new master .

3） Semi-synchronous replication

　　 Between asynchronous replication and full synchronous replication , The main library does not return to the client immediately after executing a transaction committed by the client , Instead, wait for at least one of the slave libraries to receive and write relay log Is returned to the client . As opposed to asynchronous replication , Semi-synchronous replication Improved data security , At the same time, it also causes a certain degree of delay , The delay is at least one TCP/IP Round-trip time . therefore , Semi synchronous replication is best used in low latency networks .

1.5.2 Realize semi synchronous replication

　　 Semi synchronous replication is based on specific modules . But very nice One thing is , In our mariadb5.5 By default, the above versions have this module .

　　 If our centos7 Installed on mariadb , We can go into the directory to check ：

[[email protected] ~]# cd /usr/lib64/mysql/plugin/

 

　　 Find our module , We can install by command , Then simply configure it to use . The following is the specific method ：

master Server ：

MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so'; MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'rpl_semi%'; MariaDB [(none)]> SET GLOBAL rpl_semi_sync_master_enabled=ON;

 

slave Server ：

MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so'; MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'rpl_semi%'; MariaDB [(none)]> SET GLOBAL rpl_semi_sync_slave_enabled = ON ; MariaDB [(none)]> stop slave;    MariaDB [(none)]> start slave;

 

 

　　 Now? , Our semi synchronous replication is started , We can check the log ：

[[email protected] ~]# tail -200 /var/log/mariadb/mariadb.log 

　　 It can also be seen from the log that our semi synchronous replication has been started .

 

　　 above , Experiment one is finished .

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They are masters and followers of each other （ Double master ）

　　 Another database architecture is dual master mode , That is to say, they are master and slave to each other , This setting is not commonly used in enterprises , But we still need to master .

Master-Master Two servers to replicate , both master, It's another server slave. such , Changes made by either party , Will be applied to the other party's database through replication .

　　 The architecture is as follows ：

 

2.1 Environmental preparation ：

centos System server 2 platform 、 Two users realize Mysql They are masters and followers of each other , Good configuration yum Source 、 Firewall OFF 、 The clock service of each node is synchronized 、 Nodes can communicate with each other through host names

2.2 Preparation steps ：

1）iptables -F && setenforce Clear firewall policy , close selinux

2） Use both servers yum Way to install Mysql service , The version is required to be consistent

3） Start two servers respectively mysql service , Make sure the service is normal

2.3 Implementation steps ：

2.3.1 Configure the first master master server

    server-id = 1　　　　　 // To configure server-id, Let the master server have a unique ID Number    

log-bin = mysql-bin　　// open Mysql journal , The log format is binary    

skip-name-resolve  　　// Turn off name resolution ,（ Not necessary ）    

relay_log = mysql-relay-bin // open Mysql journal , The log format is binary    

read_only = 1               // Set read-only permissions    

log_slave_updates = 1       // Make the updated data written in the binary log    

auto_increment_offset = 1　　　 // Indicates the number from which the growth field starts    

auto_increment_increment = 2　　// Represents the amount of each increment of the self growing field

 

2.3.2 Configure the second master master server

    server-id = 2　　　　　 // To configure server-id, Let the master server have a unique ID Number    

log-bin = mysql-bin　　// open Mysql journal , The log format is binary    

skip-name-resolve　  　// Turn off name resolution ,（ Not necessary ）   

 relay_log = mysql-relay-bin // open Mysql journal , The log format is binary    

read_only = 1               // Set read-only permissions   

 log_slave_updates = 1       // Make the updated data written in the binary log    

auto_increment_offset = 2　　　 // Indicates the number from which the growth field starts    

auto_increment_increment = 2　　// Represents the amount of each increment of the self growing field

 

2.3.3 Create a copy account

　　 Because we implement the dual master mode , So we have to create a copy account on each machine ：

 

 

2.3.4 View server status

　　 Let's check the status of the two servers , So as to lay a foundation for our next setting ：

 

 

2.3.5 Start replication thread

　　 Let's set up the two machines separately ：

　　 First , First, check the first one master The machine is set ：

MariaDB [(none)]> change master to master_host='192.168.37.222',master_user='slave',master_password='keer',master_log_file='mysql-bin.000003',master_log_pos=245; MariaDB [(none)]> start slave;

　　 next , Let's check his status ：

 

　　 Now? , Let's check the second one master Set it up ：

MariaDB [(none)]> change master to master_host='192.168.37.111',master_user='slave',master_password='keer',master_log_file='mysql-bin.000002',master_log_pos=245; MariaDB [(none)]> start slave;

　　 Let's check his status ：

 

 　　

　　 It can be seen that , Both of our machines are set up , Next , We can test it .

2.3.5 test

　　 In our configuration file , We set the start value and the growth value of the self growth field , Now let's create a self - growing table ：

MariaDB [keer]> create table test(id int PRIMARY KEY AUTO_INCREMENT,name char(20) not null);

　　 Because we set up master-slave , So use this command on any machine .

　　 After the table is created , We can insert data for testing , Let's insert multiple pieces of data to see the effect ：

The first server ：

MariaDB [keer]> insert into test(name) value('zhao'),('qian'),('sun'),('li'); Query OK, 4 rows affected (0.00 sec) Records: 4  Duplicates: 0  Warnings: 0

The second server ：

MariaDB [keer]> insert into test(name) value('zhou'),('wu'),('zheng'),('wang'); Query OK, 4 rows affected (0.00 sec) Records: 4  Duplicates: 0  Warnings: 0

　　 We have all inserted the data , Let's see how it works ：

 

　　 It can be seen that , The data inserted in two tables will not be duplicated .

　　 But now it's not as continuous as we think id , This is because , Both of our machines are plugged in at the same time 4 Data , And it is not inserted synchronously , So there will be a sequence , On the first machine sql After the execution of the statement, the... On the second machine is executed . So this happens .

　　 however , In this way, duplicate data will not be inserted . Our goal has also been achieved .