[svc]打通mysql主从同步

MySQL数据库设置主从同步

主从同步的特点:

逻辑的

异步的

主从同步的作用

1.备份

2.读写分离

主从同步的步骤

• 准备环境
  
  1, mysql版本一致 5.5以上
  
  2, 主从数据库一致

主库master修改

1.修改my.cnf

# 打开主库binlog
log-bin = mysql-bin  

# 主数据库端ID号(区别于从库)
server-id = 1

2.重启mysql,创建用于同步的账号

grant replication slave on *.* to 'rep'@'%' identified by '123456'; 

flush privileges;

查看master状态

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000009 |      196 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set

注：执行完这个步骤后不要再操作主数据库了，防止主数据库状态值变化

从库slave的修改

1.修改mysql配置

# 从数据库端ID号
server-id =2

执行同步命令

# 执行同步命令，设置主数据库ip，同步帐号密码，同步位置
mysql>change master to master_host='192.168.1.2',master_user='rep',master_password='123456',master_log_file='mysql-bin.000009',master_log_pos=196;  

# 开启同步功能
mysql>start slave;

检查从库的状态

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.2
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000009
          Read_Master_Log_Pos: 196
               Relay_Log_File: vicky-relay-bin.000002
                Relay_Log_Pos: 253
        Relay_Master_Log_File: mysql-bin.000009
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB:

注：Slave_IO_Running及Slave_SQL_Running进程必须正常运行，即YES状态，否则说明同步失败。

到这里，主从数据库设置工作已经完成，自己可以新建数据库和表，插入和修改数据，测试一下是否成功

其他可能用到的相关参数

master端

# 不同步哪些数据库
binlog-ignore-db = mysql
binlog-ignore-db = test
binlog-ignore-db = information_schema  

# 只同步哪些数据库，除此之外，其他不同步
binlog-do-db = game  

# 日志保留时间
expire_logs_days = 10  

# 控制binlog的写入频率。每执行多少次事务写入一次
# 这个参数性能消耗很大，但可减小MySQL崩溃造成的损失
sync_binlog = 5  

# 日志格式，建议mixed
# statement 保存SQL语句
# row 保存影响记录数据
# mixed 前面两种的结合
binlog_format = mixed

slave端

# 停止主从同步
mysql> stop slave;  

# 连接断开时，重新连接超时时间
mysql> change master to master_connect_retry=50;  

# 开启主从同步
mysql> start slave;

以上连接超时设置，类似方式可用于设置主数据库ip，同步帐号密码，同步位置

拓展阅读：MySQL日志格式 binlog_format

binlog的常用功能

常用功能	语句
查看bin-log开关	show variables like "%log_bin%";
查看log格式	show variables like "%format%";
查看binlog	show binary log;
刷新binlog	reset master;
-	-
查看版本	\s;
查看引擎	show variables like "%engine%";
查看字符集	show variables like "%char%";
查看slowlog	show variables like "%slow%";
-	-
建库	create database student;
建表	create table stu(id int,name char(40));
插入数据	insert into stu values (1,'maotai');
查看表字段	desc stu;
查看建表语句	show create table stu;
查询	select user,host from mysql.user;
查看错误日志	show variables like '%error%';
最大连接数(151默认)	show variables like "%max_conn%";
在mysql>执行sh命令	system ls /opt

- 查看logbin开关
mysql> show variables like "%log_bin%";
+---------------------------------+---------------------------------------+
| Variable_name                   | Value                                 |
+---------------------------------+---------------------------------------+
| log_bin                         | ON                                    |
| log_bin_basename                | /usr/local/mysql/data/mysql-bin       |
| log_bin_index                   | /usr/local/mysql/data/mysql-bin.index |
| log_bin_trust_function_creators | OFF                                   |
| log_bin_use_v1_row_events       | OFF                                   |
| sql_log_bin                     | ON                                    |
+---------------------------------+---------------------------------------+
6 rows in set (0.01 sec)

- 查看日志格式
mysql> show variables like "%format%";
+--------------------------+-------------------+
| Variable_name            | Value             |
+--------------------------+-------------------+
| binlog_format            | STATEMENT         |
| date_format              | %Y-%m-%d          |
| datetime_format          | %Y-%m-%d %H:%i:%s |
| default_week_format      | 0                 |
| innodb_file_format       | Antelope          |
| innodb_file_format_check | ON                |
| innodb_file_format_max   | Antelope          |
| time_format              | %H:%i:%s          |
+--------------------------+-------------------+
8 rows in set (0.00 sec)

- 查看二进制日志
mysql> show binary log;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'log' at line 1
mysql> show binary logs;
+------------------+-----------+
| Log_name         | File_size |
+------------------+-----------+
| mysql-bin.000001 |       120 |
+------------------+-----------+
1 row in set (0.00 sec)

- 切割日志
mysql> reset master;
Query OK, 0 rows affected (0.09 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |      120 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)