Mysql主从方案介绍
mysql主从方案主要作用：
读写分离，使数据库能支撑更大的并发。在报表中尤其重要。由于部分报表sql语句非常的慢，导致锁表，影响前台服务。如果前台使用master，报表使用slave，那么报表sql将不会造成前台锁，保证了前台速度。
发扬不同表引擎的优点。目前Myisam表的查询速度比innodb略快，而写入并发innodb比myIsam要好。那么，我们可以使用innodb作为master，处理高并发写入，使用master作为slave，接受查询。或在myisam slave中建立全文索引，解决innodb无全文索引的弱点。
热备，slave和master的数据“准实时”同步。
准备工作。先分别安装两台MYSQL。
系统环境：
OS：RHEL5.4
主：192.168.10.197
从：192.168.10.198
1、mysql 的安装这里就不介绍了，详见安装文档。
2、my.cnf配置
a、配置MASTER
点击(此处)折叠或打开
- [client]
- port = 3306
- socket = /tmp/mysql.sock
- [mysqld]
- port = 3306
- socket = /tmp/mysql.sock
- basedir=/usr/local/mysql
- datadir=/home/mysqldata
- log-slow-queries=slow_query.txt
- log-bin=mysql-bin197
- long_query_time=2
- skip-locking
- skip-name-resolve
- skip-innodb
- bind-address=192.168.10.197
- max_allowed_packet = 256M
- query_cache_size=256M
- max_connections=2000
- max_connect_errors=10000
- key_buffer_size=6000M
- read_buffer_size=32M
- read_rnd_buffer_size = 32M
- myisam_sort_buffer_size=256M
- tmp_table_size=512M
- old-passwords
- interactive_timeout=60
- wait_timeout=60
- connect_timeout=120
- table_cache=8192
- thread_cache_size=256
- sort_buffer_size=64M
- back_log = 500
- thread_concurrency=32
- server-id=1
- log-bin=mysql-bin240
- binlog-do-db=phpcmsv9
- binlog-ignore-db=mysql
- expire_logs_days=10
- [mysqldump]
- quick
- max_allowed_packet = 1024M
- [mysql]
- no-auto-rehash
- [isamchk]
- key_buffer = 1024M
- sort_buffer_size = 32M
- read_buffer = 2M
- write_buffer = 2M
- [myisamchk]
- key_buffer = 1024M
- sort_buffer_size = 32M
- read_buffer = 2M
- write_buffer = 2M
- [mysqlhotcopy]
- interactive-timeout
注释：红色是修改的部分。
其中，作为主机，server-id必须为1.
binlog_do_db为需要复制的db。 binlog_ignore_db为忽略复制的db。需要增加DB的话，就增加相应的一行。
重启master数据库，运行检查：
点击(此处)折叠或打开
- mysql> show master status; #检查是否以master形式启动了。
- +---------------------+----------+--------------+------------------+
- | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
- +---------------------+----------+--------------+------------------+
- | mysql-bin240.000001 | 2342775 | phpcmsv9 | mysql |
- +---------------------+----------+--------------+------------------+
- 1 row in set (0.00 sec)
- mysql> show variables like "%log%";
#需要看到这样的一行，说明binlog已经开启了: log_bin | ON
在master上为slave建立用户
点击(此处)折叠或打开
- mysql> grant replication slave, reload, super on *.* to 'backup'@'192.168.10.198' identified by '123';
这样，主机配置完毕。
b、slave配置
点击(此处)折叠或打开
- [client]
- port = 3306
- socket = /tmp/mysql.sock
- [mysqld]
- port = 3306
- socket = /tmp/mysql.sock
- basedir=/usr/local/mysql
- datadir=/home/mysqldata
- log-slow-queries=slow_query.txt
- log-bin=mysql-bin198
- long_query_time=2
- skip-locking
- bind-address=192.168.10.198
- skip-name-resolve
- skip-innodb
- max_allowed_packet = 256M
- query_cache_size=256M
- max_connections=2000
- max_connect_errors=10000
- key_buffer_size=6000M
- read_buffer_size=32M
- read_rnd_buffer_size = 32M
- myisam_sort_buffer_size=256M
- tmp_table_size=512M
- old-passwords
- interactive_timeout=60
- wait_timeout=60
- connect_timeout=120
- table_cache=8192
- thread_cache_size=256
- sort_buffer_size=64M
- back_log = 500
- thread_concurrency=8
- server-id=2
- master-host=192.168.10.197
- master-user=backup
- master-password=123
- master-port=3306
- replicate-do-db=phpcmsv9
- replicate-ignore-db=mysql
- master-connect-retry=60
- expire_logs_days=10
- [mysqldump]
- quick
- max_allowed_packet = 1024M
- [mysql]
- no-auto-rehash
- [isamchk]
- key_buffer = 1024M
- sort_buffer_size = 32M
- read_buffer = 2M
- write_buffer = 2M
- [myisamchk]
- key_buffer = 1024M
- sort_buffer_size = 32M
- read_buffer = 2M
- write_buffer = 2M
- [mysqlhotcopy]
- interactive-timeout
注释：红色部分为修改的地方
1.启动主服务器和从服务器服务，在从服务器192.168.17.2上使用命令slave start启动复制;
2.随便使用命令show slave status;
如果出现主从复制报错了
点击(此处)折叠或打开
- mysql> show slave status G;
- *************************** 1. row ***************************
- Slave_IO_State: Connecting to master
- Master_Host: 192.168.10.197
- Master_User: backup
- Master_Port: 3306
- Connect_Retry: 60
- Master_Log_File: mysql-bin240.000001
- Read_Master_Log_Pos: 2342431
- Relay_Log_File: localhost-relay-bin.000001
- Relay_Log_Pos: 4
- Relay_Master_Log_File: mysql-bin240.000001
- Slave_IO_Running: No
- Slave_SQL_Running: Yes
- Replicate_Do_DB: phpcmsv9
- Replicate_Ignore_DB: mysql
- 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: 2342431
- Relay_Log_Space: 106
- 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: 1130
- Last_IO_Error: error connecting to master 'backup@192.168.10.197:3306' - retry-time: 60 retries: 86400
- Last_SQL_Errno: 0
- Last_SQL_Error:
- 1 row in set (0.00 sec)
- ERROR:
- No query specified
这是由于MASTER没有赋予权限的关系
3在从服务器192.168.17.2运行slave stop;停止复制命令
4输入
点击(此处)折叠或打开
- mysql>CHANGE MASTER to MASTER_HOST='192.168.15.197', MASTER_PORT=3306, MASTER_USER='backup', MASTER_PASSWORD='123', MASTER_LOG_FILE=’mysql-bin240.000001'；, MASTER_LOG_POS=2342775;
5然后重新启动slave start 命令后
点击(此处)折叠或打开
- mysql> show slave status G;
- *************************** 1. row ***************************
- Slave_IO_State: Waiting for master to send event
- Master_Host: 192.168.10.197
- Master_User: backup
- Master_Port: 3306
- Connect_Retry: 60
- Master_Log_File: mysql-bin240.000001
- Read_Master_Log_Pos: 2342775
- Relay_Log_File: localhost-relay-bin.000002
- Relay_Log_Pos: 598
- Relay_Master_Log_File: mysql-bin240.000001
- Slave_IO_Running: Yes
- Slave_SQL_Running: Yes
- Replicate_Do_DB: phpcmsv9
- Replicate_Ignore_DB: mysql
- 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: 2342775
- Relay_Log_Space: 757
- 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:
- 1 row in set (0.00 sec)
- ERROR:
- No query specified
在从库192.168.17.2 select查询，发现后面插入的两条语句已经同步过来了，随后继续插入测试没有发现问题。