基於群組的複製（Group-basedReplication）是一種被使用在容錯系統中的技術。 Replication-group（複製群組）是由能夠相互通訊的多個伺服器（節點）組成的。
在通訊層，Groupreplication實作了一系列的機制：例如原子訊息（atomicmessage delivery）和全序化訊息（totalorderingof messages）。
這些原子化，抽象化的機制，為實現更先進的資料庫複製方案提供了強有力的支援。
MySQL Group Replication正是基於這些技術和概念，實作了多主全更新的複製協定。
簡而言之，一個Replication-group就是一組節點，每個節點都可以獨立執行事務，而讀寫事務則會在於group內的其他節點進行協調之後再commit。
因此，當一個交易準備提交時，會自動在group內進行原子性的廣播，告知其他節點變更了什麼內容/執行了什麼交易。
這種原子廣播的方式，使得這個事務在每一個節點上都保持著同樣順序。
這表示每個節點都以同樣的順序，接收了相同的事務日誌，所以每個節點以同樣的順序重演了這些事務日誌，最後整個group保持了完全一致的狀態。
然而，不同的節點上執行的事務之間有可能存在資源爭用。這種現象容易出現在兩個不同的並發事務上。
假設在不同的節點上有兩個並發事務，更新了同一行數據，那麼就會發生資源爭用。
面對這種情況，GroupReplication判定先提交的事務為有效事務，會在整個group裡面重演，後提交的事務會直接中斷，或者回滾，最後丟棄掉。
因此，這也是一個無共享的複製方案，每個節點都保存了完整的資料副本。看如下圖01.png，描述了具體的工作流程，能夠簡潔的和其他方案進行比較。這個複製方案，在某種程度上，和資料庫狀態機（DBSM）的Replication方法比較類似。
#官方下載，不過官方只保留最新的version，5.7.17這個url地址不一定長期有效，所以，需要的不一定有，我這裡在百度雲盤保留了下來，版本是5.7.17，可以隨時去下載使用，
在三台db伺服器上面設定/etc/hosts映射，如下：
| # #192.168.121.71 db1 192.168.121.24 db3 |
已安裝的資料庫伺服器：
已安裝的資料庫伺服器 |
資料目錄 # # |
#192.168.121.71（db1） | |
##/data/mysql/data |
12001 |
||
| #1C | |||
| 3317 | /data/mysql/data | #12002 |
12003
vim /etc/hosts 192.168.121.71 db1 hch_test_dbm2_121_71 192.168.121.111 db2 bpe_service 192.168.121.24 db3 hch_test_web_1_24
#
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'192.168.%' IDENTIFIED BY 'rlpbright_1927@ys';
4，安裝group replication
外掛程式
mysql> INSTALL PLUGIN group_replication SONAME 'group_replication.so'; Query OK, 0 rows affected (0.01 sec) mysql>
，設定group replication參數#確保 binlog_format 是 # #row格式。
| 設定：
set @@global.transaction_write_set_extraction = XXHASH64; set @@global.group_replication_start_on_boot = OFF; set @@global.group_replication_bootstrap_group = OFF; set @@global.group_replication_group_name = "0c6d3e5f-90e2-11e6-802e-842b2b5909d6"; set @@global.group_replication_local_address = 'db1:6606'; set @@global.group_replication_group_seeds = 'db2:6607,db3:6608';
mysql> set @@global.transaction_write_set_extraction = XXHASH64; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_start_on_boot = OFF; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_bootstrap_group = OFF; Query OK, 0 rows affected (0.00 sec) mysql> mysql>set @@global.group_replication_group_name = "0c6d3e5f-90e2-11e6-802e-842b2b5909d7"; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_local_address = 'db1:6606'; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_group_seeds = 'db2:6607,db3:6608'; Query OK, 0 rows affected (0.00 sec) mysql>
mysql> set @@global.transaction_write_set_extraction = XXHASH64; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_start_on_boot = OFF; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_bootstrap_group = OFF; Query OK, 0 rows affected (0.01 sec) mysql> set @@global.group_replication_group_name = "0c6d3e5f-90e2-11e6-802e-842b2b5909d6"; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_local_address = 'db2:6607'; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_group_seeds = 'db1:6606,db3:6608'; Query OK, 0 rows affected (0.01 sec) mysql>
mysql> set @@global.transaction_write_set_extraction = XXHASH64 ; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_start_on_boot = OFF; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_bootstrap_group = OFF ; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_group_name = "0c6d3e5f-90e2-11e6-802e-842b2b5909d6"; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_local_address = 'db3:6608' ; Query OK, 0 rows affected (0.00 sec) mysql> set @@global.group_replication_group_seeds = 'db1:6606,db2:6607' ; Query OK, 0 rows affected (0.00 sec) mysql>
（1） db1上的my.cnf配置： server-id=12001 transaction_write_set_extraction = XXHASH64 loose-group_replication_group_name = "5f847ff2-d701-11e6-819c-b8ca3af6e36c" loose-group_replication_start_on_boot = off loose-group_replication_local_address = "db1:23306" loose-group_replication_group_seeds = "db1:23306,db2:23307,db3:23308" loose-group_replication_bootstrap_group = off loose-group_replication_single_primary_mode = true loose-group_replication_enforce_update_everywhere_checks = false 登入後複製
（2）db2上的my.cnf配置： server-id=12002 transaction_write_set_extraction = XXHASH64 loose-group_replication_group_name = "5f847ff2-d701-11e6-819c-b8ca3af6e36c" loose-group_replication_start_on_boot = off loose-group_replication_local_address = "db2:23307" loose-group_replication_group_seeds = "db1:23306,db2:23307,db3:23308" loose-group_replication_bootstrap_group = off loose-group_replication_single_primary_mode = true loose-group_replication_enforce_update_everywhere_checks = false 登入後複製
（3）db3上的my.cnf配置： server-id=12003 transaction_write_set_extraction = XXHASH64 loose-group_replication_group_name = "5f847ff2-d701-11e6-819c-b8ca3af6e36c" loose-group_replication_start_on_boot = off loose-group_replication_local_address = "db3:23308" loose-group_replication_group_seeds = "db1:23306,db2:23307,db3:23308" loose-group_replication_bootstrap_group = off loose-group_replication_single_primary_mode = true loose-group_replication_enforce_update_everywhere_checks = false 登入後複製 |
配置完后，重启3个db上的mysql服务，本次案例，我们选择5.2 配置文件配置方式实现。
开始构建group replication集群，通常操作命令
mysql> CHANGE MASTER TO MASTER_USER='repl', MASTER_PASSWORD='rlpbright_1927@ys' FOR CHANNEL 'group_replication_recovery'; Query OK, 0 rows affected, 2 warnings (0.02 sec) mysql>
Db1上建立基本主库master库：
# 设置group_replication_bootstrap_group为ON是为了标示以后加入集群的服务器以这台服务器为基准，以后加入的就不需要设置。 mysql> SET GLOBAL group_replication_bootstrap_group = ON; Query OK, 0 rows affected (0.00 sec) mysql> START GROUP_REPLICATION; Query OK, 0 rows affected (1.03 sec) mysql> SELECT * FROM performance_schema.replication_group_members; +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | group_replication_applier | 3d872c2e-d670-11e6-ac1f-b8ca3af6e36c | hch_test_dbm2_121_71 | 3317 | ONLINE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ 1 row in set (0.00 sec) mysql>
Db2上启动group_replication：
Db2上mysql命令行上执行启动： mysql> START GROUP_REPLICATION; Query OK, 0 rows affected (1.02 sec) mysql> db1上后台error log显示： 2017-01-10T07:37:39.946919Z 0 [Note] Plugin group_replication reported: 'getstart group_id 41e28b21' 2017-01-10T07:58:47.624090Z 0 [Note] Plugin group_replication reported: 'getstart group_id 41e28b21' 2017-01-10T07:58:53.116957Z 0 [Note] Plugin group_replication reported: 'Marking group replication view change with view_id 14840330835325176:6' 再去master库db1上，查看group_replication成员，会有db2的显示 mysql> SELECT * FROM performance_schema.replication_group_members; +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | group_replication_applier | 3d872c2e-d670-11e6-ac1f-b8ca3af6e36c | hch_test_dbm2_121_71 | 3317 | ONLINE | | group_replication_applier | fdf2b02e-d66f-11e6-98a8-18a99b76310d | bpe_service | 3317 | ONLINE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ 2 rows in set (0.00 sec) mysql>
Db3上启动group_replication：
-- Db3命令行上执行： mysql> set global group_replication_allow_local_disjoint_gtids_join=ON; Query OK, 0 rows affected (0.00 sec) mysql> start group_replication; Query OK, 0 rows affected (1.99 sec) mysql> -- 再去master库db1上，查看group_replication成员，会有db3的显示，而且已经是ONLINE了 mysql> SELECT * FROM performance_schema.replication_group_members; +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | group_replication_applier | 3d872c2e-d670-11e6-ac1f-b8ca3af6e36c | hch_test_dbm2_121_71 | 3317 | ONLINE | | group_replication_applier | ef8ac2de-d671-11e6-9ba4-18a99b763071 | hch_test_web_1_24 | 3317 | ONLINE | | group_replication_applier | fdf2b02e-d66f-11e6-98a8-18a99b76310d | bpe_service | 3317 | ONLINE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ 3 rows in set (0.01 sec) mysql> -- db1上后台error log显示： 2017-01-10T08:00:28.866356Z 0 [Note] Plugin group_replication reported: 'getstart group_id 41e28b21' 2017-01-10T08:00:54.699130Z 0 [Note] Plugin group_replication reported: 'getstart group_id 41e28b21' 2017-01-10T08:00:56.567427Z 0 [Note] Plugin group_replication reported: 'Marking group replication view change with view_id 14840330835325176:9'
最后查看集群状态，都为ONLINE就表示OK：
mysql> SELECT * FROM performance_schema.replication_group_members; +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | group_replication_applier | 3d872c2e-d670-11e6-ac1f-b8ca3af6e36c | hch_test_dbm2_121_71 | 3317 | ONLINE | | group_replication_applier | ef8ac2de-d671-11e6-9ba4-18a99b763071 | hch_test_web_1_24 | 3317 | ONLINE | | group_replication_applier | fdf2b02e-d66f-11e6-98a8-18a99b76310d | bpe_service | 3317 | ONLINE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ 3 rows in set (0.00 sec) mysql>
测试，在master库db1上建立测试库db1，测试表t1，录入一条数据
mysql> create database db1; Query OK, 1 row affected (0.00 sec) mysql> create table db1.t1(id int,cnvarchar(32)); Query OK, 0 rows affected (0.02 sec) mysql> mysql> insert into t1 select 1,'a'; ERROR 3098 (HY000): The table does notcomply with the requirements by an external plugin. mysql> mysql> insert into t1(id,cn)values(1,'a'); ERROR 3098 (HY000): The table does notcomply with the requirements by an external plugin. mysql> mysql> -- # 这里原因是group_replaction环境下面，表必须有主键不然不允许往里insert值。所以修改表t1，将id字段设置程主键即可。 mysql> alter table t1 modify id intprimary key; Query OK, 0 rows affected (0.02 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> insert into t1 select 1,'a'; Query OK, 1 row affected (0.01 sec) Records: 1 Duplicates: 0 Warnings: 0 mysql>
去db2/db3上可以看到数据已经同步过去
mysql> select * from db1.t1; +----+------+ | id | cn | +----+------+ | 1| a | +----+------+ 1 row in set (0.00 sec) mysql>
然后在db2/db3上执行inert操作，则拒绝，因为db2、db3为readonly
mysql> insert into t1 select 2,'b'; ERROR 1290 (HY000): The MySQL server isrunning with the --super-read-only option so it cannot execute this statement mysql>
MySQL窗口报错：
ERROR 3092 (HY000): The server is notconfigured properly to be an active member of the group. Please see moredetails on error log. 后台ERROR LOG报错： [ERROR] Plugin group_replication reported:'This member has more executed transactions than those present in the group. Local transactions: f16f7f74-c283-11e6-ae37-fa163ee40410:1 > Grouptransactions: 3c992270-c282-11e6-93bf-fa163ee40410:1, aaaaaa:1-5' [ERROR]Plugin group_replication reported: 'The member contains transactions notpresent in the group. The member will now exit the group.' [Note] Plugin group_replication reported: 'Toforce this member into the group you can use the group_replication_allow_local_disjoint_gtids_joinoption'
【解决办法】：
根据提示打开group_replication_allow_local_disjoint_gtids_join选项，mysql命令行执行：
mysql> set globalgroup_replication_allow_local_disjoint_gtids_join=ON;
再执行开启组复制：
mysql> start group_replication; Query OK, 0 rows affected (7.89 sec) mysql>
在db1上查询集群组成员
mysql> SELECT * FROM performance_schema.replication_group_members; +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | group_replication_applier | 3d872c2e-d670-11e6-ac1f-b8ca3af6e36c | hch_test_dbm2_121_71 | 3317 | ONLINE | | group_replication_applier | ef8ac2de-d671-11e6-9ba4-18a99b763071 | hch_test_web_1_24 | 3317 | RECOVERING | | group_replication_applier | fdf2b02e-d66f-11e6-98a8-18a99b76310d | bpe_service | 3317 | RECOVERING | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ 3 rows in set (0.00 sec) mysql>
再查看后台error日志，
2017-01-10T09:17:39.449488Z 146 [ERROR] Slave I/O for channel 'group_replication_recovery': error connecting to master 'repl@hch_test_dbm2_121_71:3317' - retry-time: 60 retries: 1, Error_code: 2003 2017-01-10T09:17:39.450289Z 146 [Note] Slave I/O thread for channel 'group_replication_recovery' killed while connecting to master 2017-01-10T09:17:39.450449Z 146 [Note] Slave I/O thread exiting for channel 'group_replication_recovery', read up to log 'FIRST', position 4 2017-01-10T09:17:39.451579Z 144 [ERROR] Plugin group_replication reported: 'There was an error when connecting to the donor server. Check group replication recovery's connection credentials.' 2017-01-10T09:17:39.452341Z 144 [Note] Plugin group_replication reported: 'Retrying group recovery connection with another donor. Attempt 2/10' 2017-01-10T09:17:39.457834Z 0 [Note] Plugin group_replication reported: 'Marking group replication view change with view_id 14840330835325176:25' 2017-01-10T09:18:39.456629Z 144 [Note] 'CHANGE MASTER TO FOR CHANNEL 'group_replication_recovery' executed'. Previous state master_host='hch_test_dbm2_121_71', master_port= 3317, master_log_file='', master_log_pos= 4, master_bind=''. New state master_host='hch_test_dbm2_121_71', master_port= 3317, master_log_file='', master_log_pos= 4, master_bind=''. 2017-01-10T09:18:39.485250Z 144 [Note] Plugin group_replication reported: 'Establishing connection to a group replication recovery donor 3d872c2e-d670-11e6-ac1f-b8ca3af6e36c at hch_test_dbm2_121_71 port: 3317.' 2017-01-10T09:18:39.489356Z 150 [Warning] Storing MySQL user name or password information in the master info repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START SLAVE; see the 'START SLAVE Syntax' in the MySQL Manual for more information. 2017-01-10T09:18:39.493511Z 150 [ERROR] Slave I/O for channel 'group_replication_recovery': error connecting to master 'repl@hch_test_dbm2_121_71:3317' - retry-time: 60 retries: 1, Error_code: 2005 2017-01-10T09:18:39.493912Z 150 [Note] Slave I/O thread for channel 'group_replication_recovery' killed while connecting to master 2017-01-10T09:18:39.494069Z 150 [Note] Slave I/O thread exiting for channel 'group_replication_recovery', read up to log 'FIRST', position 4 2017-01-10T09:18:39.495155Z 144 [ERROR] Plugin group_replication reported: 'There was an error when connecting to the donor server. Check group replication recovery's connection credentials.' 2017-01-10T09:18:39.496838Z 144 [Note] Plugin group_replication reported: 'Retrying group recovery connection with another donor. Attempt 3/10'
【解决办法】：
看报错[ERROR] Slave I/O for channel'group_replication_recovery': error connecting to master 'repl@hch_test_dbm2_121_71:3317'- retry-time: 60 retries: 1, Error_code:2005，连接master库不上，所以问题在这里，我们赋予的复制账号是ip的repl@'192.168.%'，所以还需要做一个hostname(hch_test_dbm2_121_71)和db1的ip地址192.168.121.71的映射关系。
建立hostname和ip映射
vim /etc/hosts 192.168.121.71 db1 hch_test_dbm2_121_71 192.168.121.111 db2 bpe_service 192.168.121.24 db3 hch_test_web_1_24
然后在db2上执行如下命令后重新开启group_replication即可。
mysql> stop group_replication; Query OK, 0 rows affected (0.02 sec) mysql> start group_replication; Query OK, 0 rows affected (5.68 sec) mysql>
再去master库db1上，查看group_replication成员，会有db2的显示
mysql> SELECT * FROM performance_schema.replication_group_members; +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ | group_replication_applier | 3d872c2e-d670-11e6-ac1f-b8ca3af6e36c | hch_test_dbm2_121_71 | 3317 | ONLINE | | group_replication_applier | fdf2b02e-d66f-11e6-98a8-18a99b76310d | bpe_service | 3317 | ONLINE | +---------------------------+--------------------------------------+----------------------+-------------+--------------+ 2 rows in set (0.00 sec) mysql>
操作问题
mysql> mysql> START GROUP_REPLICATION; ERROR 3092 (HY000): The server is notconfigured properly to be an active member of the group. Please see moredetails on error log.
【解决办法】：
mysql> SET GLOBALgroup_replication_bootstrap_group = ON; Query OK, 0 rows affected (0.00 sec) mysql> START GROUP_REPLICATION; Query OK, 0 rows affected (1.03 sec) mysql>
以上是詳細介紹MySQL Group Replication[Single-Primary Mode]的建置部署過程的詳細內容。更多資訊請關注PHP中文網其他相關文章！
