Replication,复制是高可用的基础，MHA、mycat等中间件的底层都依赖复制原理 master 主实例 slave 从实例 分类：默认的异步复制,5.5版本后的半同步复制,5.6版本新增的GTID复制,5.7版本的多源复制
Replication,复制是高可用的基础，MHA、mycat等中间件的底层都依赖复制原理
master 主实例 slave 从实例
分类：默认的异步复制,5.5版本后的半同步复制,5.6版本新增的GTID复制,5.7版本的多源复制,基于组提交的并行复制和增强半同步复制
复制方法：1.传统方法：基于binlog日志复制 2.GTID：基于事物复制
binlog可以有不同的格式：基于语句、基于行数据、混合（行数据复制是默认）
下面搭建下常规的异步复制
必要条件：server_id在主从之间不同；主库开启binlog，建议从库也开启方便架构扩展
首先编辑my.cnf开启binlog并设置server_id
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 (0.00 sec)
mysql> ^DBye
[root@localhost ~]$ cat /etc/my.cnf
[mysqld]
datadir=/usr/local/mysql/data
log_bin=mysql-bin
server_id=1
[root@localhost ~]$
然后创建主从复制的用户，之前实验已经创建了scott用户，就用这个了，再赋权(因为会密码会明文保存在slave的master.info所以实际上应该单独建立个只有复制权限的用户)
mysql> grant replication slave on *.* to 'scott'@'%';
Query OK, 0 rows affected (0.00 sec)
表加锁停止修改
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.01 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000003 | 556 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> drop table tmp;
ERROR 122
然后将主库全量备份一个传给备库,可以直接data目录打包过去(innodb不推荐)或者直接mysqldump
[root@localhost ~]$ mysqldump --all-databases -uroot -pmysql --master-data > dbdump.db
mysqldump: [Warning] Using a password on the command line interface can be insecure.
[root@localhost ~]$ ls
dbdump.db
[root@localhost ~]$ scp dbdump.db 192.0.1.11:~
The authenticity of host '192.0.1.11 (192.0.1.11)' can't be established.
ECDSA key fingerprint is SHA256:pmk8Q9EnT+TugRZ5rb2bc0GP20ZV3LkeuXP/Jrw5tbs.
ECDSA key fingerprint is MD5:13:d1:4a:14:3a:4d:fd:33:56:15:f9:1f:2f:44:87:2c.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.0.1.11' (ECDSA) to the list of known hosts.
root@192.0.1.11's password:
dbdump.db
然后在备库中应用
mysql> source dbdump.db
从库中配置主库信息
mysql> change master to
-> master_host='192.0.1.10',
-> master_user='scott',
-> master_password='tiger',
-> master_port=3306,
-> master_log_file='mysql-bin.000003',
-> master_log_pos=556;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql>
开启同步
mysql> start slave ;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave statusG;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.0.1.10
Master_User: scott
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000003
Read_Master_Log_Pos: 556
Relay_Log_File: localhost-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000003
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: 556
Relay_Log_Space: 531
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: 1
Master_UUID: 531fa6d1-627f-11e9-8dc7-000c297887a1
Master_Info_File: /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)
ERROR:
No query specified
mysql>
释放主库锁定
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)
好了验证下，主库中插入记录，从库立刻就有了
