Mysql主從方案的實現

轉自：http://blog.chinaunix.net/uid-25266990-id-3239588.html

Mysql主從方案介紹

mysql主從方案主要作用：

讀寫分離，使數據庫能支撐更大的併發。在報表中尤其重要。由於部分報表sql語句非常的慢，導致鎖表，影響前臺服務。如果前臺使用master，報表使用slave，那麼報表sql將不會造成前臺鎖，保證了前臺速度。

發揚不同表引擎的優點。目前Myisam表的查詢速度比innodb略快，而寫入併發innodb比myIsam要好。那麼，我們可以使用innodb作爲master，處理高併發寫入，使用master作爲slave，接受查詢。或在myisam slave中建立全文索引，解決innodb無全文索引的弱點。

熱備，slave和master的數據“準實時”同步。

準備工作。先分別安裝兩臺MYSQL。

系統環境：

OS：RHEL5.4

主：192.168.10.197

從：192.168.10.198

1、mysql 的安裝這裏就不介紹了，詳見安裝文檔。

2、my.cnf配置

a、配置MASTER

點擊(此處)摺疊或打開

1. [client]
2. 
   
3. port = 3306
4. 
   
5. socket = /tmp/mysql.sock
6. 
   
7. [mysqld]
8. 
   
9. port = 3306
10. 
    
11. socket = /tmp/mysql.sock
12. 
    
13. basedir=/usr/local/mysql
14. 
    
15. datadir=/home/mysqldata
16. 
    
17. log-slow-queries=slow_query.txt
18. 
    
19. log-bin=mysql-bin197
20. 
    
21. long_query_time=2
22. 
    
23. skip-locking
24. 
    
25. skip-name-resolve
26. 
    
27. skip-innodb
28. 
    
29. bind-address=192.168.10.197
30. 
    
31. max_allowed_packet = 256M
32. 
    
33. query_cache_size=256M
34. 
    
35. max_connections=2000
36. 
    
37. max_connect_errors=10000
38. 
    
39. key_buffer_size=6000M
40. 
    
41. read_buffer_size=32M
42. 
    
43. read_rnd_buffer_size = 32M
44. 
    
45. myisam_sort_buffer_size=256M
46. 
    
47. tmp_table_size=512M
48. 
    
49. old-passwords
50. 
    
51. interactive_timeout=60
52. 
    
53. wait_timeout=60
54. 
    
55. connect_timeout=120
56. 
    
57. table_cache=8192
58. 
    
59. thread_cache_size=256
60. 
    
61. sort_buffer_size=64M
62. 
    
63. back_log = 500
64. 
    
65. thread_concurrency=32
66. 
    
67. server-id=1
68. 
    
69. log-bin=mysql-bin240
70. 
    
71. binlog-do-db=phpcmsv9
72. 
    
73. binlog-ignore-db=mysql
74. 
    
75. expire_logs_days=10
76. 
    
77. [mysqldump]
78. 
    
79. quick
80. 
    
81. max_allowed_packet = 1024M
82. 
    
83. [mysql]
84. 
    
85. no-auto-rehash
86. 
    
87. [isamchk]
88. 
    
89. key_buffer = 1024M
90. 
    
91. sort_buffer_size = 32M
92. 
    
93. read_buffer = 2M
94. 
    
95. write_buffer = 2M
96. 
    
97. [myisamchk]
98. 
    
99. key_buffer = 1024M
100. 
     
101. sort_buffer_size = 32M
102. 
     
103. read_buffer = 2M
104. 
     
105. write_buffer = 2M
106. 
     
107. [mysqlhotcopy]
108. 
     
109. interactive-timeout

註釋：紅色是修改的部分。

其中，作爲主機，server-id必須爲1.

binlog_do_db爲需要複製的db。 binlog_ignore_db爲忽略複製的db。需要增加DB的話，就增加相應的一行。

重啓master數據庫，運行檢查：

點擊(此處)摺疊或打開

1. mysql> show master status; #檢查是否以master形式啓動了。
2. 
   
3. +---------------------+----------+--------------+------------------+
4. 
   
5. | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
6. 
   
7. +---------------------+----------+--------------+------------------+
8. 
   
9. | mysql-bin240.000001 | 2342775 | phpcmsv9 | mysql |
10. 
    
11. +---------------------+----------+--------------+------------------+
12. 
    
13. 1 row in set (0.00 sec)
14. 
    
15. mysql> show variables like "%log%";

#需要看到這樣的一行，說明binlog已經開啓了: log_bin | ON

在master上爲slave建立用戶

點擊(此處)摺疊或打開

1. mysql> grant replication slave, reload, super on *.* to 'backup'@'192.168.10.198' identified by '123';

這樣，主機配置完畢。
b、slave配置

點擊(此處)摺疊或打開

1. [client]
2. 
   
3. port = 3306
4. 
   
5. socket = /tmp/mysql.sock
6. 
   
7. [mysqld]
8. 
   
9. port = 3306
10. 
    
11. socket = /tmp/mysql.sock
12. 
    
13. basedir=/usr/local/mysql
14. 
    
15. datadir=/home/mysqldata
16. 
    
17. log-slow-queries=slow_query.txt
18. 
    
19. log-bin=mysql-bin198
20. 
    
21. long_query_time=2
22. 
    
23. skip-locking
24. 
    
25. bind-address=192.168.10.198
26. 
    
27. skip-name-resolve
28. 
    
29. skip-innodb
30. 
    
31. max_allowed_packet = 256M
32. 
    
33. query_cache_size=256M
34. 
    
35. max_connections=2000
36. 
    
37. max_connect_errors=10000
38. 
    
39. key_buffer_size=6000M
40. 
    
41. read_buffer_size=32M
42. 
    
43. read_rnd_buffer_size = 32M
44. 
    
45. myisam_sort_buffer_size=256M
46. 
    
47. tmp_table_size=512M
48. 
    
49. old-passwords
50. 
    
51. interactive_timeout=60
52. 
    
53. wait_timeout=60
54. 
    
55. connect_timeout=120
56. 
    
57. table_cache=8192
58. 
    
59. thread_cache_size=256
60. 
    
61. sort_buffer_size=64M
62. 
    
63. back_log = 500
64. 
    
65. thread_concurrency=8
66. 
    
67. server-id=2
68. 
    
69. master-host=192.168.10.197
70. 
    
71. master-user=backup
72. 
    
73. master-password=123
74. 
    
75. master-port=3306
76. 
    
77. replicate-do-db=phpcmsv9
78. 
    
79. replicate-ignore-db=mysql
80. 
    
81. master-connect-retry=60
82. 
    
83. expire_logs_days=10
84. 
    
85. [mysqldump]
86. 
    
87. quick
88. 
    
89. max_allowed_packet = 1024M
90. 
    
91. [mysql]
92. 
    
93. no-auto-rehash
94. 
    
95. [isamchk]
96. 
    
97. key_buffer = 1024M
98. 
    
99. sort_buffer_size = 32M
100. 
     
101. read_buffer = 2M
102. 
     
103. write_buffer = 2M
104. 
     
105. [myisamchk]
106. 
     
107. key_buffer = 1024M
108. 
     
109. sort_buffer_size = 32M
110. 
     
111. read_buffer = 2M
112. 
     
113. write_buffer = 2M
114. 
     
115. [mysqlhotcopy]
116. 
     
117. interactive-timeout

註釋：紅色部分爲修改的地方

1.啓動主服務器和從服務器服務，在從服務器192.168.17.2上使用命令slave start啓動複製;

2.隨便使用命令show slave status;

如果出現主從複製報錯了

點擊(此處)摺疊或打開

1. mysql> show slave status \G;
2. 
   
3. *************************** 1. row ***************************
4. 
   
5. Slave_IO_State: Connecting to master
6. 
   
7. Master_Host: 192.168.10.197
8. 
   
9. Master_User: backup
10. 
    
11. Master_Port: 3306
12. 
    
13. Connect_Retry: 60
14. 
    
15. Master_Log_File: mysql-bin240.000001
16. 
    
17. Read_Master_Log_Pos: 2342431
18. 
    
19. Relay_Log_File: localhost-relay-bin.000001
20. 
    
21. Relay_Log_Pos: 4
22. 
    
23. Relay_Master_Log_File: mysql-bin240.000001
24. 
    
25. Slave_IO_Running: No
26. 
    
27. Slave_SQL_Running: Yes
28. 
    
29. Replicate_Do_DB: phpcmsv9
30. 
    
31. Replicate_Ignore_DB: mysql
32. 
    
33. Replicate_Do_Table:
34. 
    
35. Replicate_Ignore_Table:
36. 
    
37. Replicate_Wild_Do_Table:
38. 
    
39. Replicate_Wild_Ignore_Table:
40. 
    
41. Last_Errno: 0
42. 
    
43. Last_Error:
44. 
    
45. Skip_Counter: 0
46. 
    
47. Exec_Master_Log_Pos: 2342431
48. 
    
49. Relay_Log_Space: 106
50. 
    
51. Until_Condition: None
52. 
    
53. Until_Log_File:
54. 
    
55. Until_Log_Pos: 0
56. 
    
57. Master_SSL_Allowed: No
58. 
    
59. Master_SSL_CA_File:
60. 
    
61. Master_SSL_CA_Path:
62. 
    
63. Master_SSL_Cert:
64. 
    
65. Master_SSL_Cipher:
66. 
    
67. Master_SSL_Key:
68. 
    
69. Seconds_Behind_Master: NULL
70. 
    
71. Master_SSL_Verify_Server_Cert: No
72. 
    
73. Last_IO_Errno: 1130
74. 
    
75. Last_IO_Error: error connecting to master '[email protected]:3306' - retry-time: 60 retries: 86400
76. 
    
77. Last_SQL_Errno: 0
78. 
    
79. Last_SQL_Error:
80. 
    
81. 1 row in set (0.00 sec)
82. 
    
83. ERROR:
84. 
    
85. No query specified

這是由於MASTER沒有賦予權限的關係

3在從服務器192.168.17.2運行slave stop;停止複製命令

4輸入

點擊(此處)摺疊或打開

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然後重新啓動slave start 命令後

點擊(此處)摺疊或打開

1. mysql> show slave status \G;
2. 
   
3. *************************** 1. row ***************************
4. 
   
5. Slave_IO_State: Waiting for master to send event
6. 
   
7. Master_Host: 192.168.10.197
8. 
   
9. Master_User: backup
10. 
    
11. Master_Port: 3306
12. 
    
13. Connect_Retry: 60
14. 
    
15. Master_Log_File: mysql-bin240.000001
16. 
    
17. Read_Master_Log_Pos: 2342775
18. 
    
19. Relay_Log_File: localhost-relay-bin.000002
20. 
    
21. Relay_Log_Pos: 598
22. 
    
23. Relay_Master_Log_File: mysql-bin240.000001
24. 
    
25. Slave_IO_Running: Yes
26. 
    
27. Slave_SQL_Running: Yes
28. 
    
29. Replicate_Do_DB: phpcmsv9
30. 
    
31. Replicate_Ignore_DB: mysql
32. 
    
33. Replicate_Do_Table:
34. 
    
35. Replicate_Ignore_Table:
36. 
    
37. Replicate_Wild_Do_Table:
38. 
    
39. Replicate_Wild_Ignore_Table:
40. 
    
41. Last_Errno: 0
42. 
    
43. Last_Error:
44. 
    
45. Skip_Counter: 0
46. 
    
47. Exec_Master_Log_Pos: 2342775
48. 
    
49. Relay_Log_Space: 757
50. 
    
51. Until_Condition: None
52. 
    
53. Until_Log_File:
54. 
    
55. Until_Log_Pos: 0
56. 
    
57. Master_SSL_Allowed: No
58. 
    
59. Master_SSL_CA_File:
60. 
    
61. Master_SSL_CA_Path:
62. 
    
63. Master_SSL_Cert:
64. 
    
65. Master_SSL_Cipher:
66. 
    
67. Master_SSL_Key:
68. 
    
69. Seconds_Behind_Master: 0
70. 
    
71. Master_SSL_Verify_Server_Cert: No
72. 
    
73. Last_IO_Errno: 0
74. 
    
75. Last_IO_Error:
76. 
    
77. Last_SQL_Errno: 0
78. 
    
79. Last_SQL_Error:
80. 
    
81. 1 row in set (0.00 sec)
82. 
    
83. ERROR:
84. 
    
85. No query specified

在從庫192.168.17.2 select查詢，發現後面插入的兩條語句已經同步過來了，隨後繼續插入測試沒有發現問題。