mysql5.7 MGR集群搭建

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mysql5.7 MGR集群搭建部署

此文章由隊員（諄諄）擬寫

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最近看了一下mysql5.7的MGR集群挺不錯的，有單主和多主模式，于是乎搭建測試了一下效果還不錯，我指的不錯是搭建和維護方面都比較簡單。網上絕大多數都是單主模式，當然我這里也是，為了加深印象，特意記錄一下搭建過程，等以后再去嘗試多主模式，相信大家現在數據庫的瓶頸基本都是在寫，讀寫分離雖然是一種可行的解決方案，但是如果數據量很大，寫一樣會有問題，雖然有些解決方案能部署多個主節點，能同時進行讀寫，但是腦裂又是一個嚴重的問題，所以這里MGR集群內置了自動化腦裂防護機制又得到了很多人的青睞，這里MGR簡稱MySQL Group Replication是MySQL官方于2016年12月推出的一個全新的高可用與高擴展的解決方案。注意本文這里不再闡述原理性的東西。
注意：我這里采用編譯安裝的方式，如果想簡單直接yum安裝mysql5.7也行，mysql編譯安裝需要的磁盤空間還是比較大的，一般在7G左右，所以要提前規劃好，用三個節點比較接近生產環境，而且更直接清晰。
詳細部署信息如下：

1、三臺機器準備工作

1. rpm -qa mysql mariadb

如果有則卸載即可！
寫入hosts文件映射關系，集群用得到
192.168.2.25    apache
192.168.2.26    nginx
192.168.2.30    kibana
2、安裝依賴包

1. yum install gcc gcc-c++ ncurses-devel -y

3、安裝cmake，下載地址：https://cmake.org/download/

1. tar zxvf cmake-3.7.2.tar.gz

2. cd make-3.7.2

3. ./configure

4. gmake && gmake install

4、安裝boost，因為mysql5.7需要，注意這里下載版本是1_59_0和mysql版本是對應的，如果你的MySQL版本和我的不一樣，不添加-DWITH_BOOST這個參數時它會報錯告訴你需要下載boost的哪個版本。

1. tar zxvf boost_1_59_0.tar.gz

2. cp -r boost_1_59_0 /usr/local/boost

5、安裝mysql5.7.17及初始化操作

1. groupadd mysql

2. useradd -M -s /sbin/nologin mysql -g mysql

3. tar zxvf mysql-5.7.17.tar.gz

4. cd mysql-5.7.17

5. cmake -DCMAKE_INSTALL_PREFIX=/data/mysql -DSYSCONFDIR=/etc -DDEFAULT_CHARSET=utf8 -DDEFAULT_COLLATION=utf8_general_ci -DWITH_EXTRA_CHARSETS=all -DWITH_BOOST=/usr/local/boost

6. make

7. make install

8. chown -R mysql.mysql /data/mysql

9. mv /etc/my.cnf /etc/my.cnf.default

10. cp /data/mysql/support-files/my-default.cnf /etc/my.cnf

11. /data/mysql/bin/mysqld –initialize –user=mysql –basedir=/data/mysql –datadir=/data/mysql/data                 //注意初始化會生成一個隨機的密碼，請牢記

12. echo “PATH=$PATH:/data/mysql/bin” >> /etc/profile

13. source /etc/profile

14. cp /data/mysql/support-files/mysql.server /etc/rc.d/init.d/mysqld

15. chmod +x /etc/rc.d/init.d/mysqld

以上步驟在三臺機器上都需要執行

6、開始搭建MGR集群環境，修改第一個節點的my.cnf文件，內容如下：

1. # For advice on how to change settings please see

2. # http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

3. # *** DO NOT EDIT THIS FILE. It’s a template which will be copied to the

4. # *** default location during install, and will be replaced if you

5. # *** upgrade to a newer version of MySQL.

6. 
   

7. [mysqld]

8. 
   

9. # Remove leading # and set to the amount of RAM for the most important data

10. # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.

11. # innodb_buffer_pool_size = 128M

12. 
    

13. # Remove leading # to turn on a very important data integrity option: logging

14. # changes to the binary log between backups.

15. # log_bin

16. 
    

17. # These are commonly set, remove the # and set as required.

18. basedir = /data/mysql

19. datadir = /data/mysql/data

20. port = 3306

21. socket = /data/mysql/data/mysql.sock

22. log-error = /data/mysql/data/mysqld.log

23. pid-file = /data/mysql/data/mysqld.pid

24. 
    

25. # Remove leading # to set options mainly useful for reporting servers.

26. # The server defaults are faster for transactions and fast SELECTs.

27. # Adjust sizes as needed, experiment to find the optimal values.

28. # join_buffer_size = 128M

29. # sort_buffer_size = 2M

30. # read_rnd_buffer_size = 2M

31. 
    

32. sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

33. 
    

34. # Group Replication

35. server_id = 1

36. gtid_mode = ON

37. enforce_gtid_consistency = ON

38. master_info_repository = TABLE

39. relay_log_info_repository = TABLE

40. binlog_checksum = NONE

41. log_slave_updates = ON

42. log_bin = binlog

43. binlog_format= ROW

44. 
    

45. transaction_write_set_extraction = XXHASH64

46. loose-group_replication_group_name = ‘ce9be252-2b71-11e6-b8f4-00212844f856’

47. loose-group_replication_start_on_boot = off

48. loose-group_replication_local_address = ‘192.168.2.25:33061’

49. loose-group_replication_group_seeds =’192.168.2.25:33061,192.168.2.26:33061,192.168.2.30:33061′

50. loose-group_replication_bootstrap_group = off

51. 
    

52. [client]

53. socket = /data/mysql/data/mysql.sock

啟動mysql服務
/etc/init.d/mysqld start

1. set sql_log_bin=0;

2. create user rpl_user@’%’;

3. grant replication slave on *.* to rpl_user@’%’ identified by ‘rpl_pass’;

4. flush privileges;

5. set sql_log_bin=1;

6. change master to master_user=’rpl_user’,master_password=’rpl_pass’ for channel ‘group_replication_recovery’;

7. install PLUGIN group_replication SONAME ‘group_replication.so’;

8. set global group_replication_bootstrap_group=ON;

9. start group_replication;

10. set global group_replication_bootstrap_group=OFF;

11. select * from performance_schema.replication_group_members;

顯示結果如下：

如果出現ONLINE，說明正常，這就是主節點，再搭建兩個從節點。

7、第二個節點加入集群，復制剛剛的第一個節點的主配置文件my.cnf，只需要修改兩個地方就行，已經用紅色標注

1. # For advice on how to change settings please see

2. # http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

3. # *** DO NOT EDIT THIS FILE. It’s a template which will be copied to the

4. # *** default location during install, and will be replaced if you

5. # *** upgrade to a newer version of MySQL.

6. 
   

7. [mysqld]

8. 
   

9. # Remove leading # and set to the amount of RAM for the most important data

10. # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.

11. # innodb_buffer_pool_size = 128M

12. 
    

13. # Remove leading # to turn on a very important data integrity option: logging

14. # changes to the binary log between backups.

15. # log_bin

16. 
    

17. # These are commonly set, remove the # and set as required.

18. basedir = /data/mysql

19. datadir = /data/mysql/data

20. port = 3306

21. socket = /data/mysql/data/mysql.sock

22. log-error = /data/mysql/data/mysqld.log

23. pid-file = /data/mysql/data/mysqld.pid

24. 
    

25. # Remove leading # to set options mainly useful for reporting servers.

26. # The server defaults are faster for transactions and fast SELECTs.

27. # Adjust sizes as needed, experiment to find the optimal values.

28. # join_buffer_size = 128M

29. # sort_buffer_size = 2M

30. # read_rnd_buffer_size = 2M

31. 
    

32. sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

33. 
    

34. # Group Replication

35. server_id = 2

36. gtid_mode = ON

37. enforce_gtid_consistency = ON

38. master_info_repository = TABLE

39. relay_log_info_repository = TABLE

40. binlog_checksum = NONE

41. log_slave_updates = ON

42. log_bin = binlog

43. binlog_format= ROW

44. 
    

45. transaction_write_set_extraction = XXHASH64

46. loose-group_replication_group_name = ‘ce9be252-2b71-11e6-b8f4-00212844f856’

47. loose-group_replication_start_on_boot = off

48. loose-group_replication_local_address = ‘192.168.2.26:33061’

49. loose-group_replication_group_seeds =’192.168.2.25:33061,192.168.2.26:33061,192.168.2.30:33061′

50. loose-group_replication_bootstrap_group = off

51. 
    

52. [client]

53. socket = /data/mysql/data/mysql.sock

第二個節點執行如下命令：

1. set sql_log_bin=0;

2. create user rpl_user@’%’;

3. grant replication slave on *.* to rpl_user@’%’ identified by ‘rpl_pass’;

4. set sql_log_bin=1;

5. change master to master_user=’rpl_user’,master_password=’rpl_pass’ for channel ‘group_replication_recovery’;

6. install plugin group_replication SONAME ‘group_replication.so’;

7. set global group_replication_allow_local_disjoint_gtids_join=ON;

8. start group_replication;

顯示結果如下：

同理第三個節點加入操作方法也和第二個節點一樣。
截圖如下：

查詢哪個是主節點：

從上圖來看很明顯apache主機是主節點。

測試步驟：
1、在主庫上創建一個庫，然后創建表，在兩個從庫上查詢數據是否同步？
2、兩個從庫只能執行查詢操作？
2、手動關閉主庫，確認兩個從庫其中一個是否會變成主庫？而且是MEMBER_ID第一個字母按優先級排列的接管主庫？

日常維護步驟：
1、如果從庫某一節點關閉

1. start group_replication;

2、如果所有的庫都關閉后，第一個庫作為主庫首先執行

1. set global group_replication_bootstrap_group=ON;

2. start group_replication;

剩下的庫直接執行即可！

1. start group_replication;

3、如果主庫故障，會自動從兩個從庫選出一個主庫，主庫啟動后再次執行如下命令后會變成從庫

1. start group_replication;