mysql5.6 主从同步
主库IP：192.168.220.3
从库IP：192.168.220.4
1、主库配置编辑my.cnf：
# For advice on how to change settings please see # http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html # *** DO NOT EDIT THIS FILE. It's a template which will be copied to the # *** default location during install, and will be replaced if you # *** upgrade to a newer version of MySQL. [mysqld] # Remove leading # and set to the amount of RAM for the most important data # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%. # innodb_buffer_pool_size = 128M # Remove leading # to turn on a very important data integrity option: logging # changes to the binary log between backups. # log_bin # These are commonly set, remove the # and set as required. basedir = /usr/mysql datadir = /usr/mysql/data port = 3306 server_id = 1 socket = /tmp/mysql.sock lower_case_table_names = 1 log-bin = mysql-bin # 启用二进制日志 server-id = 3 # 服务器唯一ID 取IP最后一段 sync_binlog = 1 # 每次事务提交则将cache中的数据写入磁盘并同步执行同步指令，此时最安全但是性能损失最大 binlog_format = mixed # binlog日志格式，mysql默认采用 binlog-do-db = db1 # 同步数据库 binlog-ignore-db = mysql # 忽略同步的数据库 binlog-ignore-db = performance_schema binlog-ignore-db = information_schema binlog_checksum=NONE # Remove leading # to set options mainly useful for reporting servers. # The server defaults are faster for transactions and fast SELECTs. # Adjust sizes as needed, experiment to find the optimal values. # join_buffer_size = 128M # sort_buffer_size = 2M # read_rnd_buffer_size = 2M sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
2、主库mysql创建同步账号
grant replication slave on *.* to slave@192.168.220.4 indentified by 'qwe123'
flush privileges;
3、主库状态
mysql> show master status;
+------------------+----------+--------------+---------------------------------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+---------------------------------------------+-------------------+
| mysql-bin.000002 | 402 | db1 | mysql,performance_schema,information_schema | |
+------------------+----------+--------------+---------------------------------------------+-------------------+
记录下二进制日志文件名和位置
4、从库配置文件配置
# 启用二进制日志 log-bin=mysql-bin # 服务器唯一ID，一般取IP最后一段 server-id=4 relay-log-index = slave-relay-bin.index relay-log = slave-relay-bin sync_master_info = 1 sync_relay_log = 1 sync_relay_log_info = 1
5、从库mysql中配置连接主库
change master to master_host='192.168.220.3',master_user='slave',master_password='qwe123', master_log_file='mysql-bin.000002',master_log_pos=402;
6、开始同步
mysql> start slave;
7、查看同步状态
mysql> show slave status\G;
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
备注：如果主从不同步处理方案
先上Master库：
mysql>show processlist; 查看下进程是否Sleep太多。发现很正常。
show master status; 也正常。
mysql> show master status;
+-------------------+----------+--------------+-------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+-------------------------------+
| mysqld-bin.000001 | 3260 | | mysql,test,information_schema |
+-------------------+----------+--------------+-------------------------------+
1 row in set (0.00 sec)
再到Slave上查看
mysql> show slave status\G
Slave_IO_Running: Yes
Slave_SQL_Running: No
可见是Slave不同步
下面介绍两种解决方法：
方法一：忽略错误后，继续同步
该方法适用于主从库数据相差不大，或者要求数据可以不完全统一的情况，数据要求不严格的情况
解决：
stop slave;
#表示跳过一步错误，后面的数字可变
set global sql_slave_skip_counter =1;
start slave;
之后再用mysql> show slave status\G 查看：
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
ok，现在主从同步状态正常
方式二：重新做主从，完全同步
该方法适用于主从库数据相差较大，或者要求数据完全统一的情况
解决步骤如下：
1.先进入主库，进行锁表，防止数据写入
使用命令：
mysql> flush tables with read lock;
注意：该处是锁定为只读状态，语句不区分大小写
2.进行数据备份
#把数据备份到mysql.bak.sql文件
[root@server01 mysql]#mysqldump -uroot -p -hlocalhost > mysql.bak.sql
3.查看master 状态
mysql> show master status;
+-------------------+----------+--------------+-------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+-------------------------------+
| mysqld-bin.000001 | 3260 | | mysql,test,information_schema |
+-------------------+----------+--------------+-------------------------------+
1 row in set (0.00 sec)
4.把mysql备份文件传到从库机器，进行数据恢复
#使用scp命令
[root@server01 mysql]# scp mysql.bak.sql root@192.168.220.4:/tmp/
5.停止从库的状态
mysql> stop slave;
6.然后到从库执行mysql命令，导入数据备份
mysql> source /tmp/mysql.bak.sql
7.设置从库同步，注意该处的同步点，就是主库show master status信息里的| File| Position两项
change master to master_host = '192.168.220.3', master_user = 'slave', master_port=3306, master_password='qwe123', master_log_file = 'mysqld-bin.000001', master_log_pos=3260;
8.重新开启从同步
mysql> start slave;
9.查看同步状态
mysql> show slave status\G 查看：
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
