Mysql主从方案的实现

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

1. [client]
2. port = 3306
3. socket = /tmp/mysql.sock
4. [mysqld]
5. port = 3306
6. socket = /tmp/mysql.sock
7. basedir=/usr/local/mysql
8. datadir=/home/mysqldata
9. log-slow-queries=slow_query.txt
10. log-bin=mysql-bin197
11. long_query_time=2
12. skip-locking
13. skip-name-resolve
14. skip-innodb
15. bind-address=192.168.10.197
16. max_allowed_packet = 256M
17. query_cache_size=256M
18. max_connections=2000
19. max_connect_errors=10000
20. key_buffer_size=6000M
21. read_buffer_size=32M
22. read_rnd_buffer_size = 32M
23. myisam_sort_buffer_size=256M
24. tmp_table_size=512M
25. old-passwords
26. interactive_timeout=60
27. wait_timeout=60
28. connect_timeout=120
29. table_cache=8192
30. thread_cache_size=256
31. sort_buffer_size=64M
32. back_log = 500
33. thread_concurrency=32
34. server-id=1
35. log-bin=mysql-bin240
36. binlog-do-db=phpcmsv9
37. binlog-ignore-db=mysql
38. expire_logs_days=10
39. [mysqldump]
40. quick
41. max_allowed_packet = 1024M
42. [mysql]
43. no-auto-rehash
44. [isamchk]
45. key_buffer = 1024M
46. sort_buffer_size = 32M
47. read_buffer = 2M
48. write_buffer = 2M
49. [myisamchk]
50. key_buffer = 1024M
51. sort_buffer_size = 32M
52. read_buffer = 2M
53. write_buffer = 2M
54. [mysqlhotcopy]
55. 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

1. mysql> show master status; #检查是否以master形式启动了。
2. +---------------------+----------+--------------+------------------+
3. | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
4. +---------------------+----------+--------------+------------------+
5. | mysql-bin240.000001 | 2342775 | phpcmsv9 | mysql |
6. +---------------------+----------+--------------+------------------+
7. 1 row in set (0.00 sec)
8. 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

1. 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

1. [client]
2. port = 3306
3. socket = /tmp/mysql.sock
4. [mysqld]
5. port = 3306
6. socket = /tmp/mysql.sock
7. basedir=/usr/local/mysql
8. datadir=/home/mysqldata
9. log-slow-queries=slow_query.txt
10. log-bin=mysql-bin198
11. long_query_time=2
12. skip-locking
13. bind-address=192.168.10.198
14. skip-name-resolve
15. skip-innodb
16. max_allowed_packet = 256M
17. query_cache_size=256M
18. max_connections=2000
19. max_connect_errors=10000
20. key_buffer_size=6000M
21. read_buffer_size=32M
22. read_rnd_buffer_size = 32M
23. myisam_sort_buffer_size=256M
24. tmp_table_size=512M
25. old-passwords
26. interactive_timeout=60
27. wait_timeout=60
28. connect_timeout=120
29. table_cache=8192
30. thread_cache_size=256
31. sort_buffer_size=64M
32. back_log = 500
33. thread_concurrency=8
34. server-id=2
35. master-host=192.168.10.197
36. master-user=backup
37. master-password=123
38. master-port=3306
39. replicate-do-db=phpcmsv9
40. replicate-ignore-db=mysql
41. master-connect-retry=60
42. expire_logs_days=10
43. [mysqldump]
44. quick
45. max_allowed_packet = 1024M
46. [mysql]
47. no-auto-rehash
48. [isamchk]
49. key_buffer = 1024M
50. sort_buffer_size = 32M
51. read_buffer = 2M
52. write_buffer = 2M
53. [myisamchk]
54. key_buffer = 1024M
55. sort_buffer_size = 32M
56. read_buffer = 2M
57. write_buffer = 2M
58. [mysqlhotcopy]
59. 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

1. mysql> show slave status \G;
2. *************************** 1. row ***************************
3. Slave_IO_State: Connecting to master
4. Master_Host: 192.168.10.197
5. Master_User: backup
6. Master_Port: 3306
7. Connect_Retry: 60
8. Master_Log_File: mysql-bin240.000001
9. Read_Master_Log_Pos: 2342431
10. Relay_Log_File: localhost-relay-bin.000001
11. Relay_Log_Pos: 4
12. Relay_Master_Log_File: mysql-bin240.000001
13. Slave_IO_Running: No
14. Slave_SQL_Running: Yes
15. Replicate_Do_DB: phpcmsv9
16. Replicate_Ignore_DB: mysql
17. Replicate_Do_Table:
18. Replicate_Ignore_Table:
19. Replicate_Wild_Do_Table:
20. Replicate_Wild_Ignore_Table:
21. Last_Errno: 0
22. Last_Error:
23. Skip_Counter: 0
24. Exec_Master_Log_Pos: 2342431
25. Relay_Log_Space: 106
26. Until_Condition: None
27. Until_Log_File:
28. Until_Log_Pos: 0
29. Master_SSL_Allowed: No
30. Master_SSL_CA_File:
31. Master_SSL_CA_Path:
32. Master_SSL_Cert:
33. Master_SSL_Cipher:
34. Master_SSL_Key:
35. Seconds_Behind_Master: NULL
36. Master_SSL_Verify_Server_Cert: No
37. Last_IO_Errno: 1130
38. Last_IO_Error: error connecting to master 'backup@192.168.10.197:3306' - retry-time: 60 retries: 86400
39. Last_SQL_Errno: 0
40. Last_SQL_Error:
41. 1 row in set (0.00 sec)
42. ERROR:
43. 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

1. 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

1. mysql> show slave status \G;
2. *************************** 1. row ***************************
3. Slave_IO_State: Waiting for master to send event
4. Master_Host: 192.168.10.197
5. Master_User: backup
6. Master_Port: 3306
7. Connect_Retry: 60
8. Master_Log_File: mysql-bin240.000001
9. Read_Master_Log_Pos: 2342775
10. Relay_Log_File: localhost-relay-bin.000002
11. Relay_Log_Pos: 598
12. Relay_Master_Log_File: mysql-bin240.000001
13. Slave_IO_Running: Yes
14. Slave_SQL_Running: Yes
15. Replicate_Do_DB: phpcmsv9
16. Replicate_Ignore_DB: mysql
17. Replicate_Do_Table:
18. Replicate_Ignore_Table:
19. Replicate_Wild_Do_Table:
20. Replicate_Wild_Ignore_Table:
21. Last_Errno: 0
22. Last_Error:
23. Skip_Counter: 0
24. Exec_Master_Log_Pos: 2342775
25. Relay_Log_Space: 757
26. Until_Condition: None
27. Until_Log_File:
28. Until_Log_Pos: 0
29. Master_SSL_Allowed: No
30. Master_SSL_CA_File:
31. Master_SSL_CA_Path:
32. Master_SSL_Cert:
33. Master_SSL_Cipher:
34. Master_SSL_Key:
35. Seconds_Behind_Master: 0
36. Master_SSL_Verify_Server_Cert: No
37. Last_IO_Errno: 0
38. Last_IO_Error:
39. Last_SQL_Errno: 0
40. Last_SQL_Error:
41. 1 row in set (0.00 sec)
42. ERROR:
43. 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。