2018-10-26 01:07:32
近期业务需要想要把mysql从RDS迁移至EC2。由于主库业务不能有任何问题，不确定的情况下不修改主库基础参数，在EC2上重做从库。
1，申请一个配置有多可用区的测试实例：giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com
2，授权复制帐号和测试帐号（sysbench做测试）
GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'repl'@'117.160.%' IDENTIFIED BY 'repl';
grant select,create,index,insert,update,delete,drop on *.* to gktest@'117.160.%' identified by 'giikin';
#使其立刻生效
flush privileges;
3，得到主库上的binlog位置
>show master status\G
*************************** 1. row ***************************
File: mysql-bin-changelog.000023
Position: 5768524
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.01 sec)
4，在EC2准备一台从库，指定好主从关系
>CHANGE MASTER TO MASTER_HOST='giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com', MASTER_PORT=3306, MASTER_LOG_FILE='mysql-bin-changelog.000023', MASTER_LOG_POS=5768524, MASTER_USER='repl', MASTER_PASSWORD='repl';
Query OK, 0 rows affected, 2 warnings (0.02 sec)
>start slave;
Query OK, 0 rows affected (0.00 sec)
>show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin-changelog.000023
Read_Master_Log_Pos: 5768524
Relay_Log_File: relay-log.000002
Relay_Log_Pos: 293
Relay_Master_Log_File: mysql-bin-changelog.000023
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: mysql
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table: mysql.%
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 5768524
Relay_Log_Space: 460
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: 459205842
Master_UUID: 46da27c8-007c-11e7-9b5b-06051bcfdaae
Master_Info_File: /data/dbdata/mysqldata/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
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
1 row in set (0.00 sec)
5，用sysbench往RDS写入数据的时候，通过重启实例来模拟主库failover的时候的对从库的影响。
/usr/local/sysbench/bin/sysbench --mysql-host=giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com --mysql-port=3306 --mysql-user=gktest --mysql-password=giikin --mysql-db=failovertest --oltp-tables-count=5 --oltp-table-size=6000000 --max-requests=100000000 --test=/usr/local/sysbench/tests/db/select.lua prepare
6，此时连mysql的时候会报错，管理后台显示该实例正在修复中
$ mysql -uroot -p -hgiikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com
ERROR 2003 (HY000): Can't connect to MySQL server on 'giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com' (110)
7，查看slave的复制状态是否正常。
>show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event ##正在等待同步
Master_Host: giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin-changelog.000024
Read_Master_Log_Pos: 24121968
Relay_Log_File: relay-log.000004
Relay_Log_Pos: 24122141
Relay_Master_Log_File: mysql-bin-changelog.000024
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: mysql
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table: mysql.%
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 24121968
Relay_Log_Space: 24122365
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: 459205842
Master_UUID: 46da27c8-007c-11e7-9b5b-06051bcfdaae
Master_Info_File: /data/dbdata/mysqldata/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
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
1 row in set (0.00 sec)
多次执行show slave statusG命令发现复制状态都显示正常，但是位置一直卡在mysql-bin-changelog.000024 24121968这里不动，此时RDS上面的主库一直有用sysbench写数据进来。可以断定虽然复现状态显示正常，但是其实连接已经失效。
8，在RDS主库上面查看一下binary log的信息可以发现从库已经执行完了mysql-bin-changelog.000024日志的所有event,从日志偏移量可以看出mysql-bin-changelog.000024是failover之前的日志，mysql-bin-changelog.000025是failover之后的日志。
>show binary logs;
+----------------------------+-----------+
| Log_name | File_size |
+----------------------------+-----------+
| mysql-bin-changelog.000020 | 134243795 |
| mysql-bin-changelog.000021 | 111694820 |
| mysql-bin-changelog.000022 | 134243505 |
| mysql-bin-changelog.000023 | 134244377 |
| mysql-bin-changelog.000024 | 24121968 |
| mysql-bin-changelog.000025 | 134244377 |
| mysql-bin-changelog.000026 | 134243504 |
| mysql-bin-changelog.000027 | 134243503 |
| mysql-bin-changelog.000028 | 114316703 |
+----------------------------+-----------+
9 rows in set (0.01 sec)
9，挠头想了半天怎么继续从RDS主库拉日志..，最后谷歌到可能由于EC2的从库连接RDS是用的域名，failover后这个域名已经指向了另外一个ip，而当前复制的连接一直没有释放，在是连的之前对应的ip。
感觉很有道理，然后在从库上面执行stop slave; start slave;再查看复制状态时，发现并不是这个问题。
>show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com
Master_User: root
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin-changelog.000039
Read_Master_Log_Pos: 660
Relay_Log_File: looaon-relay-bin.000004
Relay_Log_Pos: 706
Relay_Master_Log_File: mysql-bin-changelog.000025###############此处不同步
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1146
Last_Error: Error 'Table 'mysql.rds_heartbeat2' doesn't exist' on query. Default database: 'mysql'. Query: 'INSERT INTO mysql.rds_heartbeat2(id, value) values (1,1540479644062) ON DUPLICATE KEY UPDATE value = 1540479644062'
Skip_Counter: 0
Exec_Master_Log_Pos: 405
Relay_Log_Space: 23301
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: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 1146
Last_SQL_Error: Error 'Table 'mysql.rds_heartbeat2' doesn't exist' on query. Default database: 'mysql'. Query: 'INSERT INTO mysql.rds_heartbeat2(id, value) values (1,1540479644062) ON DUPLICATE KEY UPDATE value = 1540479644062'
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1670357905
Master_SSL_Crl:
Master_SSL_Crlpath:
Using_Gtid: No
Gtid_IO_Pos:
1 row in set (0.00 sec)
测试：
Master_Log_File可以获取到，由此可见主库放RDS，从库放EC2这样的形式理论上是可行的。
未解决问题：
Relay_Master_Log_File 不同步
未解报错：
Last_Error: Error 'Table 'mysql.rds_heartbeat2' doesn't exist' on query. Default database: 'mysql'. Query: 'INSERT INTO mysql.rds_heartbeat2(id, value) values (1,1540479644062) ON DUPLICATE KEY UPDATE value = 1540479644062'
重点配置：
给账号一个maseter
change maste to
master_host=‘giikin_test’
master_usr='repl'
master_password='repl'
master_log_file='mysql-bin.ooooo1'，
master_log_pos=660
用到的命令
CHANGE MASTER TO MASTER_HOST='giikin-test.civxfbosrcnl.ap-southeast-1.rds.amazonaws.com', MASTER_PORT=3306, MASTER_LOG_FILE='mysql-bin-changelog.000024', MASTER_LOG_POS=660, MASTER_USER='root', MASTER_PASSWORD='looaon.com';
查看状态
show slave status\G
查看数据库表
show databases;
重置slave
start slave; #使配置生效
stop slave; #停止服务
reset slave; #启动服务
设置ecs为只读库
show global variables like "%read_only%";
flush tables with read lock;
set global read_only=1;
show global variables like "%read_only%";
set global read_only=1; #1是只读，0是读写
可能遇到的问题：
主库failover时需要马上在从库上面执行stop slave;start slave;命令，这样从库不至于落后主库同步太长时间。