MGR集群搭建及配置过程
作者:苦逼运维 发布时间:2024-01-24 18:56:14
MGR全称MySQL Group Replication(Mysql组复制),是MySQL官方于2016年12月推出的一个全新的高可用与高扩展的解决方案。MGR提供了高可用、高扩展、高可靠的MySQL集群服务。在MGR出现之前,用户常见的MySQL高可用方式,无论怎么变化架构,本质就是Master-Slave架构。MySQL 5.7版本开始支持无损半同步复制(lossless semi-sync replication),从而进一步提示数据复制的强一致性。
MGR是MySQL数据库未来发展的一个重要方向。
注意:根据本人测试group_replication.so插件是mysql-community-server安装包中携带,如果是rpm安装或yum安装存放地址为/usr/lib64/mysql/plugin/目录下,看下图。另外在安装5.7.16版本时是没有这个插件,而在安装5.7.20版本有这个插件,推测这是一个5.7.16到5.7.20之间新加的插件,个人建议安装5.7.20以上的版本。另外大家请在安装好mysql后查看一下是否存在这个插件。
如果提示group_replication.so不存在,或提示有问题并且查看时发现group_replication.so不存在,请重点看一下mysql的版本。(我搜了一大圈,没有一个人说这个问题。表示怀疑自己,如果我错了,请留言。)
(1).MGR的特性
高一致性。基于原生复制及paxos协议的组复制技术,并以插件的方式提供,提供一致数据安全保证;
高容错性。只要不是大多数节点坏掉就可以继续工作,有自动检测机制,当不同节点产生资源争用冲突时,不会出现错误,按照先到者优先原则进行处理,并且内置了自动化脑裂防护机制;
高扩展性。节点的新增和移除都是自动的,新节点加入后,会自动从其他节点上同步状态,直到新节点和其他节点保持一致,如果某节点被移除了,其他节点自动更新组信息,自动维护新的组信息;
高灵活性。有单主模式和多主模式,单主模式下,会自动选主,所有更新操作都在主上进行;多主模式下,所有server都可以同时处理更新操作。
(2).搭建MGR的基础结构要求和使用限制(重点)
基础结构要求:1.引擎必须为innodb,因为需事务支持在commit时对各节点进行冲突检查;2.每个表必须有主键,在进行事务冲突检测时需要利用主键值对比;3.必须开启binlog且为row格式;4.开启GTID,且主从状态信息存于表中(--master-info-repository=TABLE 、--relay-log-info-repository=TABLE),--log-slave-updates打开;5.一致性检测设置--transaction-write-set-extraction=XXHASH64。
使用限制:1.RP和普通复制binlog校验不能共存,需设置--binlog-checksum=none;2.不支持gap lock(间隙锁),隔离级别需设置为read_committed;3.不支持对表进行锁操作(lock /unlock table),不会发送到其他节点执行 ,影响需要对表进行加锁操作的情况,列入mysqldump全表备份恢复操作;4.不支持serializable(序列化)隔离级别;5.DDL语句不支持原子性,不能检测冲突,执行后需自行校验是否一;6.多主模式下不支持外键,单主模式下支持外键;最多9个节点,超过9台无法加入集群
(3).实验环境
youxi1192.168.1.6CentOS7.6Mysql5.7.26端口号3306server-id=1
youxi2192.168.1.7CentOS7.6Mysql5.7.26端口号3306server-id=2
youxi3192.168.1.8CentOS7.6Mysql5.7.26端口号3306server-id=3
另外,三台服务器上都进行IP的映射(如果此处不映射,请修改/etc/my.cnf配置文件中对应的域名为IP地址)
[root@youxi1 ~]# vim /etc/hosts
192.168.1.6 youxi1.cn youxi1//长域名和短域名只要映射一个即可
192.168.1.7 youxi2.cn youxi2
192.168.1.8 youxi3.cn youxi3
(1).单主模式
我是在空数据库下操作,如果主数据集已存在数据,需要将主数据库的数据导出再导入到从数据库。另外还需保证引擎为innodb,每个表必须存在主键。
1)以youxi1作为主服务器,对youxi1进行配置
创建一个复制用的用户
mysql> grant replication slave on *.* to 'repl'@'192.168.1.%' identified by '12345678';
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
修改配置文件,加入到[mysqld]模块下。然后重启mysqld
[root@youxi1 ~]# vim /etc/my.cnf
server-id=1//Mysql服务ID
gtid-mode=on//全局事务
enforce-gtid-consistency=on//强制GTID的一致性
master-info-repository=TABLE//将master.info元数据保存在系统表中
relay-log-info-repository=TABLE//将relay.info元数据保存在系统表中
binlog-checksum=none//禁用二进制日志事件校验
log-slave-updates=on//级联复制
log-bin=binlog//开启二进制日志记录
binlog-format=ROW//以行的格式记录
transaction-write-set-extraction=XXHASH64//使用哈希算法将其编码为散列
loose-group_replication_group_name='ce9be252-2b71-11e6-b8f4-00212844f856'//加入的组名,可以修改,只要格式对
loose-group_replication_start_on_boot=off//不自动启用组复制集群
loose-group_replication_local_address='youxi1:33061'//以本机端口33061接受来自组中成员的传入连接
loose-group_replication_group_seeds='youxi1:33061,youxi2:33062,youxi3:33063'//组中成员访问表
loose-group_replication_bootstrap_group=off//不启用引导组
[root@youxi1 ~]# systemctl restart mysqld
注意:如果防火墙是打开的,记得添加mysql的端口号。
[root@youxi1 ~]# firewall-cmd --permanent --zone=public --add-port={3306,33061}/tcp
success
[root@youxi1 ~]# firewall-cmd --reload
success
[root@youxi1 ~]# firewall-cmd --zone=public --list-ports
3306/tcp 33061/tcp
修改master信息,构建组复制(group replication)集群信息
mysql> change master to master_user='repl',master_password='12345678' for channel 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.04 sec)
安装组复制(group replication)插件,并查看组件信息
mysql> install PLUGIN group_replication SONAME 'group_replication.so';
Query OK, 0 rows affected (0.21 sec)
mysql> show plugins;//查看组件是否安装成功
+----------------------------+----------+--------------------+----------------------+---------+
| Name | Status | Type | Library | License |
+----------------------------+----------+--------------------+----------------------+---------+
| binlog | ACTIVE | STORAGE ENGINE | NULL | GPL |
| mysql_native_password | ACTIVE | AUTHENTICATION | NULL | GPL |
| sha256_password | ACTIVE | AUTHENTICATION | NULL | GPL |
| CSV | ACTIVE | STORAGE ENGINE | NULL | GPL |
| MEMORY | ACTIVE | STORAGE ENGINE | NULL | GPL |
| InnoDB | ACTIVE | STORAGE ENGINE | NULL | GPL |
| INNODB_TRX | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_LOCKS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_LOCK_WAITS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMPMEM | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMPMEM_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP_PER_INDEX | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP_PER_INDEX_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_BUFFER_PAGE | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_BUFFER_PAGE_LRU | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_BUFFER_POOL_STATS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_TEMP_TABLE_INFO | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_METRICS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_DEFAULT_STOPWORD | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_DELETED | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_BEING_DELETED | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_CONFIG | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_INDEX_CACHE | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_INDEX_TABLE | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_TABLES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_TABLESTATS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_INDEXES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_COLUMNS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_FIELDS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_FOREIGN | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_FOREIGN_COLS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_TABLESPACES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_DATAFILES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_VIRTUAL | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL |
| MRG_MYISAM | ACTIVE | STORAGE ENGINE | NULL | GPL |
| PERFORMANCE_SCHEMA | ACTIVE | STORAGE ENGINE | NULL | GPL |
| ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | GPL |
| BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | GPL |
| FEDERATED | DISABLED | STORAGE ENGINE | NULL | GPL |
| partition | ACTIVE | STORAGE ENGINE | NULL | GPL |
| ngram | ACTIVE | FTPARSER | NULL | GPL |
| validate_password | DISABLED | VALIDATE PASSWORD | validate_password.so | GPL |
| group_replication | ACTIVE | GROUP REPLICATION | group_replication.so | GPL |
+----------------------------+----------+--------------------+----------------------+---------+
46 rows in set (0.00 sec)
作为主服务器需要由这台服务器开启引导,开启组复制(group replication)集群
mysql> set global group_replication_bootstrap_group=on;//开启组复制引导
Query OK, 0 rows affected (0.00 sec)
mysql> start group_replication;//开启组复制
Query OK, 0 rows affected (2.24 sec)
mysql> set global group_replication_bootstrap_group=off;//关闭组复制引导
Query OK, 0 rows affected (0.00 sec)
查看到添加到组复制集群的服务器信息
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | c9e3662b-9020-11e9-94aa-000c29721e89 | youxi1 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
1 row in set (0.00 sec)
2)对youxi2进行配置
创建一个复制用的用户
mysql> grant replication slave on *.* to 'repl'@'192.168.1.%' identified by '12345678';
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
修改配置文件,加入到[mysqld]模块下。然后重启mysqld
[root@youxi2 ~]# vim /etc/my.cnf
server-id=2//修改
gtid-mode=on
enforce-gtid-consistency=on
master-info-repository=TABLE
relay-log-info-repository=TABLE
binlog-checksum=none
log-slave-updates=on
log-bin=binlog
binlog-format=ROW
transaction-write-set-extraction=XXHASH64
loose-group_replication_group_name='ce9be252-2b71-11e6-b8f4-00212844f856'
loose-group_replication_start_on_boot=off
loose-group_replication_local_address='youxi2:33062'//修改
loose-group_replication_group_seeds='youxi1:33061,youxi2:33062,youxi3:33063'
loose-group_replication_bootstrap_group=off
[root@youxi2 ~]# systemctl restart mysqld
注意:如果防火墙是打开的,记得添加mysql的端口号。
[root@youxi2 ~]# firewall-cmd --permanent --zone=public --add-port={3306,33062}/tcp
success
[root@youxi2 ~]# firewall-cmd --reload
success
[root@youxi2 ~]# firewall-cmd --zone=public --list-ports
3306/tcp 33062/tcp
修改master信息,构建组复制(group replication)集群信息
mysql> change master to master_user='repl',master_password='12345678' for channel 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.05 sec)
安装组复制(group replication)插件
mysql> install PLUGIN group_replication SONAME 'group_replication.so';
Query OK, 0 rows affected (0.35 sec)
把youxi2加到之前的组复制(group replication)
mysql> set global group_replication_allow_local_disjoint_gtids_join=ON;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> start group_replication;
Query OK, 0 rows affected, 1 warning (5.92 sec)
查看到添加到组复制集群的服务器信息
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 8fbf8b41-84fe-11e9-897e-000c29f27e52 | youxi2 | 3306 | ONLINE |
| group_replication_applier | c9e3662b-9020-11e9-94aa-000c29721e89 | youxi1 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
2 rows in set (0.00 sec)
3)youxi3的配置与youxi2的配置几乎一样,只需在/etc/my.cnf修改server-id和loose-group_replication_local_address即可。
查看一下组复制集群信息
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 74df3399-91b8-11e9-be5f-000c299fdf40 | youxi3 | 3306 | ONLINE |
| group_replication_applier | 8fbf8b41-84fe-11e9-897e-000c29f27e52 | youxi2 | 3306 | ONLINE |
| group_replication_applier | c9e3662b-9020-11e9-94aa-000c29721e89 | youxi1 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.01 sec)
注意:如果防火墙是打开的,记得添加mysql的端口号。
[root@youxi3 ~]# firewall-cmd --permanent --zone=public --add-port=3306/tcp
success
[root@youxi3 ~]# firewall-cmd --permanent --zone=public --add-port=33063/tcp
success
[root@youxi3 ~]# firewall-cmd --reload
success
[root@youxi3 ~]# firewall-cmd --zone=public --list-ports
3306/tcp 33063/tcp
4)测试
在youxi1上创建数据
mysql> create database test_db;
Query OK, 1 row affected (0.00 sec)
mysql> use test_db;
Database changed
mysql> create table user_tb(id int key,name varchar(20));//id是主键,引擎默认是innodb
Query OK, 0 rows affected (0.02 sec)
mysql> insert into user_tb values(1,'zhangsan');
Query OK, 1 row affected (0.08 sec)
在youxi2上查看
mysql> select * from test_db.user_tb;
+----+----------+
| id | name |
+----+----------+
| 1 | zhangsan |
+----+----------+
1 row in set (0.00 sec)
在youxi3上查看
mysql> select * from test_db.user_tb;
+----+----------+
| id | name |
+----+----------+
| 1 | zhangsan |
+----+----------+
1 row in set (0.00 sec)
5)那么怎么区分主从服务器
MGR区分主从服务器使用show variables like '%read_only%';查看read_only相关参数。如果是主服务器(youxi1),会显示如下:
mysql> show variables like '%read_only%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
如果是从服务器(youxi2)会显示如下:
mysql> show variables like '%read_only%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | ON |
| super_read_only | ON |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.01 sec)
6)查看当前服务器的组复制集群参数设置列表
mysql> show variables like 'group_replication%';
+----------------------------------------------------+----------------------------------------+
| Variable_name | Value |
+----------------------------------------------------+----------------------------------------+
| group_replication_allow_local_disjoint_gtids_join | OFF |
| group_replication_allow_local_lower_version_join | OFF |
| group_replication_auto_increment_increment | 7 |
| group_replication_bootstrap_group | OFF |
| group_replication_components_stop_timeout | 31536000 |
| group_replication_compression_threshold | 1000000 |
| group_replication_enforce_update_everywhere_checks | OFF |
| group_replication_exit_state_action | READ_ONLY |
| group_replication_flow_control_applier_threshold | 25000 |
| group_replication_flow_control_certifier_threshold | 25000 |
| group_replication_flow_control_mode | QUOTA |
| group_replication_force_members | |
| group_replication_group_name | ce9be252-2b71-11e6-b8f4-00212844f856 |
| group_replication_group_seeds | youxi1:33061,youxi2:33062,youxi3:33063 |
| group_replication_gtid_assignment_block_size | 1000000 |
| group_replication_ip_whitelist | AUTOMATIC |
| group_replication_local_address | youxi1:33061 |
| group_replication_member_weight | 50 |
| group_replication_poll_spin_loops | 0 |
| group_replication_recovery_complete_at | TRANSACTIONS_APPLIED |
| group_replication_recovery_reconnect_interval | 60 |
| group_replication_recovery_retry_count | 10 |
| group_replication_recovery_ssl_ca | |
| group_replication_recovery_ssl_capath | |
| group_replication_recovery_ssl_cert | |
| group_replication_recovery_ssl_cipher | |
| group_replication_recovery_ssl_crl | |
| group_replication_recovery_ssl_crlpath | |
| group_replication_recovery_ssl_key | |
| group_replication_recovery_ssl_verify_server_cert | OFF |
| group_replication_recovery_use_ssl | OFF |
| group_replication_single_primary_mode | ON |
| group_replication_ssl_mode | DISABLED |
| group_replication_start_on_boot | OFF |
| group_replication_transaction_size_limit | 0 |
| group_replication_unreachable_majority_timeout | 0 |
+----------------------------------------------------+----------------------------------------+
36 rows in set (0.00 sec)
7)如果主服务器出问题,MGR会自动切换主服务器
将youxi1的mysqld人为关闭
[root@youxi1 ~]# systemctl stop mysqld
之后前往youxi2和youxi3查看谁是主服务器
mysql> show variables like '%read_only%';//这是youxi2的
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | ON |
| super_read_only | ON |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.01 sec)
mysql> show variables like '%read_only%';//这是youxi3的
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.02 sec)
可以看到youxi3变成了主服务器,那么尝试在youxi3中插入数据
mysql> insert into test_db.user_tb values(2,'lisi');
Query OK, 1 row affected (0.14 sec)
再到youxi2中查看数据
mysql> select * from test_db.user_tb;
+----+----------+
| id | name |
+----+----------+
| 1 | zhangsan |
| 2 | lisi |
+----+----------+
2 rows in set (0.00 sec)
(2).多主模式
1)在创建时就启用多主模式
在创建时就启用多主模式只需在修改配置文件/etc/my.cnf时多加两行参数。其余保持不变
loose-group_replication_single_primary_mode=off//关闭单master模式
loose-group_replication_enforce_update_everywhere_checks=ON//多主一致性检查
2)由单主模式改为多主模式
由单主改为多主时,一样需要所有服务器配置信息增加两行参数,为了下次开启就是多主模式
loose-group_replication_single_primary_mode=off//关闭单master模式
loose-group_replication_enforce_update_everywhere_checks=ON//开启多主一致性检查
然后全部服务器停止组复制(GROUP_REPLICATION)集群,并设置参数
mysql> stop GROUP_REPLICATION;
Query OK, 0 rows affected (9.51 sec)
mysql> set global group_replication_single_primary_mode=off;//关闭单主模式
Query OK, 0 rows affected (0.00 sec)
mysql> set global group_replication_enforce_update_everywhere_checks=ON;//开启多主一致性检查
Query OK, 0 rows affected (0.00 sec)
选择其中一台引导组复制(GROUP_REPLICATION)集群
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 (2.13 sec)
mysql> SET GLOBAL group_replication_bootstrap_group=OFF;
Query OK, 0 rows affected (0.01 sec)
剩下的开启组复制(GROUP_REPLICATION)即可
mysql> start group_replication;
Query OK, 0 rows affected, 1 warning (6.05 sec)
最后查看非引导组复制的服务器
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 74df3399-91b8-11e9-be5f-000c299fdf40 | youxi3 | 3306 | ONLINE |
| group_replication_applier | 8fbf8b41-84fe-11e9-897e-000c29f27e52 | youxi2 | 3306 | ONLINE |
| group_replication_applier | c9e3662b-9020-11e9-94aa-000c29721e89 | youxi1 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> show variables like '%read_only%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.01 sec)
(3).如果宕机了
停掉youxi1的mysqld模拟宕机
[root@youxi1 ~]# systemctl stop mysqld
这时候查看youxi2和youxi3谁是新的master
[root@youxi2 ~]# mysql -uroot -p123456
mysql> show variables like '%read_only%';//这是youxi2的
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | ON |
| super_read_only | ON |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
[root@youxi3 ~]# mysql -uroot -p123456
mysql> show variables like '%read_only%';//这是youxi3的,可以看出youxi3成为了新的master
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
在youxi3上写入数据,这是因为生产环境数据库是一直在使用的状态,不可能等你修复后再用
[root@youxi3 ~]# mysql -uroot -p123456
mysql> insert into test_db.user_tb values(2,'lisi');
Query OK, 1 row affected (0.03 sec)
mysql> select * from test_db.user_tb;
+----+----------+
| id | name |
+----+----------+
| 1 | zhangsan |
| 2 | lisi |
+----+----------+
2 rows in set (0.00 sec)
将修好的youxi1添加回复制组
[root@youxi1 ~]# systemctl start mysqld
[root@youxi1 ~]# mysql -uroot -p123456
mysql> select * from performance_schema.replication_group_members;
+---------------------------+-----------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+-----------+-------------+-------------+--------------+
| group_replication_applier | | | NULL | OFFLINE |
+---------------------------+-----------+-------------+-------------+--------------+
1 row in set (0.00 sec)
mysql> change master to master_user='repl',master_password='12345678' for channel 'group_replication_recovery';//这一步是为了以防万一,
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> set global group_replication_allow_local_disjoint_gtids_join=ON;//将这台服务器重新添加进复制组
Query OK, 0 rows affected (0.00 sec)
mysql> start group_replication;
Query OK, 0 rows affected (3.36 sec)
mysql> select * from performance_schema.replication_group_members;//查看是否加入复制组
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 07c6f159-964f-11e9-b2c7-000c2934a723 | youxi3 | 3306 | ONLINE |
| group_replication_applier | 8247f048-962f-11e9-a210-000c2975fa5d | youxi2 | 3306 | ONLINE |
| group_replication_applier | 8b703193-962a-11e9-b582-000c29e6d627 | youxi1 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> select * from test_db.user_tb;//查看是否同步数据,没有同步请耐心等待,时间可能会长点
+----+----------+
| id | name |
+----+----------+
| 1 | zhangsan |
| 2 | lisi |
+----+----------+
2 rows in set (0.00 sec)
来源:https://www.cnblogs.com/diantong/p/11048767.html
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