十七、Mysql的主从(二)--主从复制部署

一、全年无故障率(非计划内故障停机)

 
99.9%                 ----> 0.001*365*24*60=525.6  min
99.99%                ----> 0.0001*365*24*60=52.56 min
99.999%               ----> 0.0001*365*24*60=5.256 min

二、主从介绍

随着访问量的不断增加,单台MySQL数据库服务器压力不断增加,需要对MYSQL进行优化和架构改 造,MYQSL优化如果不能明显改善压力情况,可以使用高可用、主从复制、读写分离来、拆分库、拆分 表来进行优化。 MYSQL主从复制集群在中小企业、大型企业中被广泛使用,MYSQL主从复制的目的是实现数据库冗余 备份,将Master数据库数据定时同步至Slave库中,一旦Master数据库宕机,可以将WEB应用数据库配 置快速切换至Slave数据库,确保WEB应用较高的可用性。

主要作用:实现备份; 实现故障转移; 实现读写分离。

实现的方式:

1、基于二进制日志复制的
2、主库的修改操作会记录二进制日志
3、从库会请求新的二进制日志并回放,最终达到主从数据同步
4、主从复制核心功能:
辅助备份,处理物理损坏                   
扩展新型的架构:高可用,高性能,分布式架构等

三、 主从复制前提(搭建主从的过程)

1、两台以上mysql实例 ,server_id,server_uuid不同
2、主库开启二进制日志
3、专用的复制用户
4、保证主从开启之前的某个时间点,从库数据是和主库一致。
5、告知从库,复制user,passwd,IP port,以及复制起点(change master to)
6、线程(三个):Dump thread  IO thread  SQL thread 开启(start slave)

四、主从复制搭建(Classic replication)

1、实验环境

IP:192.168.32.201  多实例3307、3308

3307为master
3308为slave

mysql多实例部署省略请参照《Mysql的多实例部署》

系统:CentOS Linux release 7.6.1810 (Core)
mysql:mysql-5.7.20-linux-glibc2.12-x86_64

2、启动多实例3307、3308

[root@vm01 ~]# systemctl start mysqld3307
[root@vm01 ~]# systemctl start mysqld3308
[root@vm01 ~]# ss -antlp|grep 330
LISTEN     0      80          :::3307             :::*                   users:(("mysqld",pid=7201,fd=31))
LISTEN     0      80          :::3308             :::*                   users:(("mysqld",pid=13480,fd=31))

3、修改my.cnf ,开启二进制日志功能和server_id(3307和3308)

主库开启server_id和log_bin日志
[root@vm01 ~]# cat /data/3307/my.cnf [mysqld] basedir=/app/mysql datadir=/data/3307/data socket=/data/3307/mysql.sock log_error=/data/3307/mysql.log port=3307 server_id=3307 log_bin=/data/3307/mysql-bin [mysql] socket=/data/3307/mysql.sock
从库开启server_id和relay_lob [root@vm01
~]# cat /data/3308/my.cnf [mysqld] basedir=/app/mysql datadir=/data/3308/data socket=/data/3308/mysql.sock log_error=/data/3308/mysql.log port=3308 server_id=3308
relay_log=/data/3308/relay-log
log_bin=/data/3308/mysql-bin [mysql] socket=/data/3308/mysql.sock [root@vm01 ~]#systemctl restart mysql3307 [root@vm01 ~]#systemctl restart mysql3308 [root@vm01 ~]# mysql -S /data/3307/mysql.sock -p -e "select @@server_id;" Enter password: +-------------+ | @@server_id | +-------------+ | 3307 | +-------------+ [root@vm01 ~]# mysql -S /data/3308/mysql.sock -p -e "select @@server_id;" Enter password: +-------------+ | @@server_id | +-------------+ | 3308 | +-------------+ [root@vm01 ~]# [root@vm01 ~]# mysql -S /data/3307/mysql.sock -p -e "select @@log_bin;" Enter password: +-----------+ | @@log_bin | +-----------+ | 1 | +-----------+ [root@vm01 ~]# mysql -S /data/3308/mysql.sock -p -e "select @@log_bin;" Enter password: +-----------+ | @@log_bin | +-----------+ | 1 | +-----------+

4、主库3307中创建复制用户

[root@vm01 ~]# mysql -S /data/3307/mysql.sock -p
[(none)]>grant replication slave on *.* to repl@'192.168.32.%' identified by '123';
Query OK, 0 rows affected, 1 warning (0.00 sec)

[(none)]>select user,host from mysql.user;
+---------------+-----------+
| user          | host      |
+---------------+-----------+
| repl          | 10.0.0.%  |
| mysql.session | localhost |
| mysql.sys     | localhost |
| root          | localhost |
+---------------+-----------+
4 rows in set (0.00 sec)

5、备份主库

mysqldump -S /data/3307/mysql.sock -A -E --master-data=2 --single-transaction  -R --triggers >/backup/full3307.sql
#二进制日志开始的点
[root@vm01 ~]# vim /backup/full3307.sql 
-- CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=444;

6、恢复从库

 
[root@vm01 ~]# mysql -S /data/3308/mysql.sock -p
[(none)]>set sql_log_bin=0;
[(none)]>source /backup/full3307.sql;
[(none)]>set sql_log_bin=1;

7、告知从库关键复制信息

[root@vm01 ~]# mysql -S /data/3308/mysql.sock -p
[none]>help change master to

[none]>CHANGE MASTER TO
  MASTER_HOST='192.168.32.201',
  MASTER_USER='repl',
  MASTER_PASSWORD='123',
  MASTER_PORT=3307,
  MASTER_LOG_FILE='mysql-bin.000001',
  MASTER_LOG_POS=444,
  MASTER_CONNECT_RETRY=10;

8、在从库3308上开启主从专用线程

[root@vm01 ~]# mysql -S /data/3308/mysql.sock -p
[(none)]>start slave;
Query OK, 0 rows affected (0.00 sec)

9、在从库3308上检查复制状态

 [root@vm01 ~]# mysql -S /data/3308/mysql.sock -p
 [(none)]>show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.32.201
                  Master_User: repl
                  Master_Port: 3307
                Connect_Retry: 10
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 738
               Relay_Log_File: vm01-relay-bin.000002
                Relay_Log_Pos: 614
        Relay_Master_Log_File: mysql-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: 738
              Relay_Log_Space: 820
              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: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 3307
                  Master_UUID: 11269f05-3166-11eb-9c7d-000c29d16f12
             Master_Info_File: /data/3308/data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: 
                Auto_Position: 0
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

#其中 Slave_IO_Running: Yes
#     Slave_SQL_Running: Yes表明主从建立完成

10、测试主从

1)查看主从库的数据是否一致
3307主库
[root@vm01 ~]# mysql -S /data/3307/mysql.sock -p
Enter password: 
[(none)]>show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

3308从库
[root@vm01 ~]# mysql -S /data/3308/mysql.sock -p
Enter password: 
[(none)]>show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

2)3307主库创建数据库ywx
[root@vm01 ~]# mysql -S /data/3307/mysql.sock -p
Enter password: 
[(none)]>create database ywx charset=utf8;
Query OK, 1 row affected (0.00 sec)

[(none)]>show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| ywx                |
+--------------------+
5 rows in set (0.00 sec)

3)查看3308从库是否同步
[root@vm01 ~]# mysql -S /data/3308/mysql.sock -p
Enter password: 
[(none)]>show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| ywx                |
+--------------------+
5 rows in set (0.00 sec)

#3308从库也有ywx数据库,主从复制部署成功!!!

 

posted @ 2020-12-01 19:37  yaowx  阅读(144)  评论(0编辑  收藏  举报