一 主库
mysql主服务器的正确配置需要指定log-bin、log-bin-index
server-id = 1
log-bin=master-bin
log-bin-index = master-bin.index
如果使用正确的配置，主机名改变后，即使mysql重启了，主从同步是能够照常进行的。
如不指定的话，binlog文件名就会依赖于主机名，如下配置
server-id = 1
log-bin
例如配置变为：
[mysqld] bind-address=0.0.0.0 port=3306 datadir=/data/mysql socket=/data/mysql/mysql.sock user=mysql skip-name-resolve slow_query_log=on long_query_time=1 slow_query_log_file=/data/mysql/mysql-slow.log innodb-file-per-table=1 innodb_flush_log_at_trx_commit = 2 log_warnings = 1 connect_timeout = 60 net_read_timeout = 120 performance_schema_max_table_instances = 400 server-id = 1 log-bin #之开启斌log日志，不指定日志名 [mysqld_safe] log-error=/data/mysql/mysqld.log pid-file=/data/mysql/mysqld.pid
主机名改变会导致binlog文件名改变，binlog文件名改变，主从同步会出问题，多台从库的话，所有从库都会出问题
[root@master mysql]# vim /etc/my.cnf
[root@master mysql]# hostnamectl set-hostname mater1
[root@master mysql]# hostname
mater1
[root@master mysql]# systemctl restart mysqld
[root@master mysql]# ll
-rw-r-----. 1 mysql mysql 56 Jul 3 11:37 auto.cnf -rw-r-----. 1 mysql mysql 304 Jul 4 10:27 ib_buffer_pool -rw-r-----. 1 mysql mysql 12582912 Jul 4 10:27 ibdata1 -rw-r-----. 1 mysql mysql 50331648 Jul 4 10:27 ib_logfile0 -rw-r-----. 1 mysql mysql 50331648 Jul 3 11:37 ib_logfile1 -rw-r-----. 1 mysql mysql 12582912 Jul 4 10:27 ibtmp1 -rw-r-----. 1 mysql mysql 1984 Jul 4 10:25 master-bin.000001 -rw-r-----. 1 mysql mysql 177 Jul 4 10:27 master-bin.000002 -rw-r-----. 1 mysql mysql 40 Jul 4 10:25 master-bin.index -rw-r-----. 1 mysql mysql 154 Jul 4 10:27 mater1-bin.000001 #改变之后的日志名 -rw-r-----. 1 mysql mysql 20 Jul 4 10:27 mater1-bin.index drwxr-x---. 2 mysql mysql 4096 Jul 3 11:37 mysql -rw-r-----. 1 mysql mysql 890 Jul 4 10:27 mysql-slow.log srwxrwxrwx. 1 mysql mysql 0 Jul 4 10:27 mysql.sock -rw-------. 1 mysql mysql 6 Jul 4 10:27 mysql.sock.lock drwxr-x---. 2 mysql mysql 8192 Jul 3 11:37 performance_schema drwxr-x---. 2 mysql mysql 8192 Jul 3 11:37 sys
查看slave的状态
mysql> show slave statusG; *************************** 1. row *************************** Slave_IO_State: Master_Host: 192.168.132.121 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000002 Read_Master_Log_Pos: 154 Relay_Log_File: relay-log.000005 Relay_Log_Pos: 369 Relay_Master_Log_File: master-bin.000002 Slave_IO_Running: No 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: 154 Relay_Log_Space: 737 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: 1236 Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file' #错误信息 Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 1 Master_UUID: 77278e78-9da8-11e9-bc6c-000c2991dd19 Master_Info_File: /data/mysql/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: 190704 10:28:05 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:
主端创建库
mysql> create database darren; Query OK, 1 row affected (0.00 sec) mysql> use darren; Database changed mysql> create table test (id int); Query OK, 0 rows affected (0.01 sec)
测试shell脚本，一直在主库插入数据
[root@master mysql]# while true ; do mysql -uroot -p123456 -e 'use darren;insert into test values (1);'; sleep 1; done
演示主从同步失败
Last_IO_Errno: 1236
Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file'
处理方法
stop slave; #停止同步
reset slave; #重置slave，这个操作会使用slave的配置丢失，由于binlog文件名改变了，所以slave得重新配置
#从新binlog的第一个binlog文件+第一个位置
主端信息：
mysql> show master logs; +-------------------+-----------+ | Log_name | File_size | +-------------------+-----------+ | mater1-bin.000001 | 10330 | +-------------------+-----------+ 1 row in set (0.00 sec) mysql> show binlog events in 'mater1-bin.000001'; +-------------------+-------+----------------+-----------+-------------+------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +-------------------+-------+----------------+-----------+-------------+------------------------------------------+ | mater1-bin.000001 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.26-log, Binlog ver: 4 | | mater1-bin.000001 | 123 | Previous_gtids | 1 | 154 | | | mater1-bin.000001 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | ...... | mater1-bin.000001 | 10136 | Query | 1 | 10210 | BEGIN | | mater1-bin.000001 | 10210 | Table_map | 1 | 10259 | table_id: 108 (darren.test) | | mater1-bin.000001 | 10259 | Write_rows | 1 | 10299 | table_id: 108 flags: STMT_END_F | | mater1-bin.000001 | 10299 | Xid | 1 | 10330 | COMMIT /* xid=209 */ | +-------------------+-------+----------------+-----------+-------------+------------------------------------------+ 196 rows in set (0.00 sec)
日志的第一个位置4
从端配置
mysql> stop slave; Query OK, 0 rows affected (0.00 sec) mysql> reset slave; Query OK, 0 rows affected (0.01 sec) mysql> change master to master_host='192.168.132.121',master_port=3306,master_user='replication',master_password='1234567',master_log_file='mater1-bin.000001',master_log_pos=4; Query OK, 0 rows affected, 2 warnings (0.01 sec) mysql> start slave; Query OK, 0 rows affected (0.00 sec) mysql> show slave statusG; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.132.121 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mater1-bin.000001 Read_Master_Log_Pos: 10330 Relay_Log_File: relay-log.000002 Relay_Log_Pos: 10545 Relay_Master_Log_File: mater1-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: 10330 Relay_Log_Space: 10746 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: 77278e78-9da8-11e9-bc6c-000c2991dd19 Master_Info_File: /data/mysql/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)
验证数据
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | darren | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) mysql> use darren; Database changed mysql> show tables; +------------------+ | Tables_in_darren | +------------------+ | test | +------------------+ 1 row in set (0.00 sec) mysql> select * from test; +------+ | id | +------+ | 1 | | 1 | | 1 | | 1 | | 1 | | 1 |
验证成功
二 从库
mysql从库正确的配置需要指定relay-log、relay-log-index
server-id = 2
relay-log = relay-log
relay-log-index = relay-log.index
如果是使用正确的配置，从库重启的话，主从同步能够照常进行。
没指定relay-log、relay-log-index
默认依赖于主机名，主机名改变，有发生mysql重启，重启后主从同步失败
配置如下：
[mysqld] bind-address=0.0.0.0 port=3306 datadir=/data/mysql socket=/data/mysql/mysql.sock user=mysql skip-name-resolve slow_query_log=on long_query_time=1 slow_query_log_file=/data/mysql/mysql-slow.log innodb-file-per-table=1 innodb_flush_log_at_trx_commit = 2 log_warnings = 1 connect_timeout = 60 net_read_timeout = 120 performance_schema_max_table_instances = 400 server-id = 2 [mysqld_safe] log-error=/data/mysql/mysqld.log pid-file=/data/mysql/mysqld.pid
[root@slave ~]# hostnamectl set-hostname slave1
[root@slave ~]# hostname
slave1
[root@slave ~]# systemctl start mysqld
[root@slave ~]# cd /data/mysql/
[root@slave mysql]# ll
-rw-r-----. 1 mysql mysql 56 Jul 3 11:56 auto.cnf drwxr-x---. 2 mysql mysql 52 Jul 4 10:41 darren -rw-r-----. 1 mysql mysql 416 Jul 4 10:58 ib_buffer_pool -rw-r-----. 1 mysql mysql 12582912 Jul 4 11:00 ibdata1 -rw-r-----. 1 mysql mysql 50331648 Jul 4 11:00 ib_logfile0 -rw-r-----. 1 mysql mysql 50331648 Jul 3 11:56 ib_logfile1 -rw-r-----. 1 mysql mysql 12582912 Jul 4 11:00 ibtmp1 -rw-r-----. 1 mysql mysql 139 Jul 4 11:00 master.info drwxr-x---. 2 mysql mysql 4096 Jul 3 11:56 mysql -rw-r-----. 1 mysql mysql 530 Jul 4 11:00 mysql-slow.log srwxrwxrwx. 1 mysql mysql 0 Jul 4 11:00 mysql.sock -rw-------. 1 mysql mysql 5 Jul 4 11:00 mysql.sock.lock drwxr-x---. 2 mysql mysql 8192 Jul 3 11:56 performance_schema -rw-r-----. 1 mysql mysql 201 Jul 4 10:41 relay-log.000001 -rw-r-----. 1 mysql mysql 10568 Jul 4 10:58 relay-log.000002 -rw-r-----. 1 mysql mysql 38 Jul 4 10:41 relay-log.index -rw-r-----. 1 mysql mysql 58 Jul 4 10:58 relay-log.info -rw-r-----. 1 mysql mysql 177 Jul 4 11:00 slave1-relay-bin.000001 #新的日志名 -rw-r-----. 1 mysql mysql 26 Jul 4 11:00 slave1-relay-bin.index drwxr-x---. 2 mysql mysql 8192 Jul 3 11:56 sys
进入数据库
mysql> start slave; ERROR 1872 (HY000): Slave failed to initialize relay log info structure from the repository mysql> show slave statusG; *************************** 1. row *************************** Slave_IO_State: Master_Host: 192.168.132.121 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mater1-bin.000001 Read_Master_Log_Pos: 10330 Relay_Log_File: relay-log.000002 Relay_Log_Pos: 10545 Relay_Master_Log_File: mater1-bin.000001 Slave_IO_Running: No 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: 1872 Last_Error: Slave failed to initialize relay log info structure from the repository Skip_Counter: 0 Exec_Master_Log_Pos: 10330 Relay_Log_Space: 0 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: 1872 Last_SQL_Error: Slave failed to initialize relay log info structure from the repository Replicate_Ignore_Server_Ids: Master_Server_Id: 0 Master_UUID: 77278e78-9da8-11e9-bc6c-000c2991dd19 Master_Info_File: /data/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: 190704 11:02:52 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)
Last_Errno: 1872
Last_Error: Slave failed to initialize relay log info structure from the repository
解决方案
需要记录当前主从同步的位置信息，一定得记录，不然同步的数据就会不全
Master_Log_File: mater1-bin.000001
Read_Master_Log_Pos: 10330
模拟主库正在写数据
[root@master mysql]# while true ; do mysql -uroot -p123456 -e 'use darren;insert into test values (1);'; sleep 1; done
从库修复
mysql> change master to master_host='192.168.132.121',master_port=3306,master_user='replication',master_password='1234567',master_log_file='mater1-bin.000001',master_log_pos=10330; 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: 192.168.132.121 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mater1-bin.000001 Read_Master_Log_Pos: 31050 Relay_Log_File: slave1-relay-bin.000002 Relay_Log_Pos: 21041 Relay_Master_Log_File: mater1-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: 31050 Relay_Log_Space: 21249 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: 77278e78-9da8-11e9-bc6c-000c2991dd19 Master_Info_File: /data/mysql/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:
验证数据一致性
主库： mysql> select * from darren.test; 118 rows in set (0.00 sec) 从库： mysql> select * from darren.test; 118 rows in set (0.00 sec)
实验完成，回复原有正确配置