文章目录
- 1.了解mysql的全同步复制
- 2. 搭建集群
- 2.1 配置server1为组的发起者
- 2.2 配置server2
- 2.3 配置server3
1.了解mysql的全同步复制
MySQL组复制是MySQL 5.7.17开始引入的新功能,为主从复制实现高可用功能
1)组复制模型
- 它支持单主模型和多主模型两种工作方式(默认是单主模型)
- 单主模型:从复制组中众多个MySQL节点中自动选举一个master节点,只有master节点可以写,其他节点自动设置为read only,当master节点故障时,会自动选举一个新的master节点,选举成功后,它将设置为可写,其他slave将指向这个新的master。
- 多主模型:复制组中的任何一个节点都可以写,因此没有master和slave的概念,只要突然故障的节点数量不太多,这个多主模型就能继续可用。
2)组复制原理
复制组由多个 server成员构成,并且组中的每个 server 成员可以独立地执行事务
但所有读写(RW)事务只有在冲突检测成功后才会提交。
只读(RO)事务不需要在冲突检测,可以立即提交。
换句话说,对于任何 RW 事务,提交操作并不是由始发 server 单向决定的,而是由组来决定是否提交。准确地说,在始发 server 上,当事务准备好提交时,该 server 会广播写入值(已改变的行)和对应的写入集(已更新的行的唯一标识符)。然后会为该事务建立一个全局的顺序。最终,这意味着所有 server 成员以相同的顺序接收同一组事务。因此,所有 server 成员以相同的顺序应用相同的更改,以确保组内一致。
组复制能够根据在一组 server 中复制系统的状态来创建具有冗余的容错系统。因此,只要它不是全部或多数 server 发生故障,即使有一些 server 故障,系统仍然可用,最多只是性能和可伸缩性降低,但它仍然可用。server 故障是孤立并且独立的。它们由组成员服务来监控,组成员服务依赖于分布式故障检测系统,其能够在任何 server 自愿地或由于意外停止而离开组时发出信号。
总之,MySQL 组复制提供了高可用性,高弹性,可靠的 MySQL 服务
3)组复制的缺点:
- 但是组复制的效率很低
当master节点写数据的时候,会等待所有的slave节点完成数据的复制,然后才继续往下进行
组复制的每一个节点都可能是slave
2. 搭建集群
实验准备:
- 我们准备三台mysql服务器来进行实验
2.1 配置server1为组的发起者
1)查看uuid:
[root@server1 ~]# cd /var/lib/mysql
[root@server1 mysql]# cat auto.cnf
[auto]
server-uuid=513e6d8e-ef42-11ea-8fe7-5254000fd593
2)编辑配置文件:
[root@server1 mysql]# vim /etc/my.cnf
# 最后添加
server_id=1
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="513e6d8e-ef42-11ea-8fe7-5254000fd593"
loose-group_replication_start_on_boot=off
loose-group_replication_local_address="172.25.5.11:33061"
loose-group_replication_group_seeds="172.25.5.11:33061,172.25.5.12:33061,172.25.5.10:33061"
loose-group_replication_bootstrap_group=off
loose-group_replication_ip_whitelist="127.0.0.1,172.25.5.0/24"
loose-group_replication_enforce_update_everywhere_checks=ON
loose-group_replication_single_primary_mode=OFF
3)开启mysql服务:
[root@server1 mysql]# systemctl restart mysqld
4)清空之前实验的mysql数据:
[root@server1 mysql]# cd /var/lib/mysql
[root@server1 mysql]# systemctl stop mysqld
[root@server1 mysql]# rm -fr *
[root@server1 mysql]# systemctl restart mysqld
5)登录数据库使用新生成登录密码:
[root@server1 mysql]# cat /var/log/mysqld.log | grep password
2020-09-05T08:47:15.103729Z 1 [Note] A temporary password is generated for root@localhost: mosejekXR9%X
[root@server1 mysql]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.24-log
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
6)修改数据库密码:
mysql> alter user root@localhost identified by "Server+147";
Query OK, 0 rows affected (0.00 sec)
7)关闭二进制日志:
mysql> SET SQL_LOG_BIN=0;
Query OK, 0 rows affected (0.00 sec)
8)创建从节点用户:
mysql> CREATE USER rpl_user@'%' IDENTIFIED BY 'Yan+123kou';
Query OK, 0 rows affected (0.00 sec)
mysql> GRANT REPLICATION SLAVE ON *.* TO rpl_user@'%';
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES; # 刷新用户授权表
Query OK, 0 rows affected (0.00 sec)
8)开启二进制日志:
SET SQL_LOG_BIN=1;
9)配置主用户:
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='Yan+123kou' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.04 sec)
10)安装组复制插件,开启组复制:
mysql> INSTALL PLUGIN group_replication SONAME 'group_replication.so';
Query OK, 0 rows affected (0.04 sec)
mysql> SET GLOBAL group_replication_bootstrap_group=ON; 组复制激活
Query OK, 0 rows affected (0.01 sec)
mysql> START GROUP_REPLICATION;
Query OK, 0 rows affected (2.86 sec)
11)关闭组复制激活,查看组的状态,当前只有一个节点在线:
mysql> SET GLOBAL group_replication_bootstrap_group=OFF;
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
| group_replication_applier | 65b6e846-ef54-11ea-baf8-5254000fd593 | server1.example.com | 3306 | ONLINE |
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
1 row in set (0.00 sec)
12)建立一个数据库test,建表写入数据:方便一会测试
mysql> CREATE DATABASE test;
Query OK, 1 row affected (0.00 sec)
mysql> USE test;
Database changed
mysql> CREATE TABLE t1 (c1 INT PRIMARY KEY, c2 TEXT NOT NULL);
Query OK, 0 rows affected (0.02 sec)
mysql> INSERT INTO t1 VALUES (1, 'Luis');
Query OK, 1 row affected (0.03 sec)
mysql> SELECT * FROM t1;
+----+------+
| c1 | c2 |
+----+------+
| 1 | Luis |
+----+------+
1 row in set (0.00 sec)
2.2 配置server2
1)server1将自己的配置文件发送给server2,server2进行修改:
[root@server1 mysql]# scp /etc/my.cnf root@172.25.5.12:/etc/
The authenticity of host '172.25.5.12 (172.25.5.12)' can't be established.
ECDSA key fingerprint is 7a:47:50:81:e2:b5:bf:17:99:f0:e2:ba:39:b7:35:2d.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.25.5.12' (ECDSA) to the list of known hosts.
root@172.25.5.12's password:
my.cnf
[root@server2 ~]# vim /etc/my.cnf
server_id=2 # 修改为自己的id
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="513e6d8e-ef42-11ea-8fe7-5254000fd593" # 使用相同的uuid
loose-group_replication_start_on_boot=off
loose-group_replication_local_address="172.25.5.12:33061" # 使用自己的ip
loose-group_replication_group_seeds="172.25.5.11:33061,172.25.5.12:33061,172.25.5.10:33061"
loose-group_replication_bootstrap_group=off
loose-group_replication_ip_whitelist="127.0.0.1,172.25.5.0/24"
loose-group_replication_enforce_update_everywhere_checks=ON
loose-group_replication_single_primary_mode=OFF
2)删除server2上之前的mysql数据:
[root@server2 ~]# systemctl stop mysqld
[root@server2 ~]# cd /var/lib/mysql
[root@server2 mysql]# ls
auto.cnf client-cert.pem ibdata1 master.info private_key.pem server-cert.pem slave-relay-bin.000005 testfile
ca-key.pem client-key.pem ib_logfile0 mysql public_key.pem server-key.pem slave-relay-bin.index testfiles
ca.pem ib_buffer_pool ib_logfile1 performance_schema relay-log.info slave-relay-bin.000004 sys
[root@server2 mysql]# rm -fr *
3)重新启动mysql服务:
[root@server2 mysql]# systemctl restart mysqld
4)查看mysql的新密码,进行登录修改密码:
[root@server2 mysql]# cat /var/log/mysqld.log | grep password
2020-09-05T09:08:54.638368Z 1 [Note] A temporary password is generated for root@localhost: hNndN%zob2+j
[root@server2 mysql]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.24-log
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> alter user root@localhost identified by "Server+147";
Query OK, 0 rows affected (0.00 sec)
5)关闭二进制日志,建立从节点用户,再次开启二进制日志:
mysql> SET SQL_LOG_BIN=0;
Query OK, 0 rows affected (0.00 sec)
mysql> CREATE USER rpl_user@'%' IDENTIFIED BY 'Yan+123kou';
Query OK, 0 rows affected (0.00 sec)
mysql> GRANT REPLICATION SLAVE ON *.* TO rpl_user@'%';
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)
mysql> SET SQL_LOG_BIN=1;
Query OK, 0 rows affected (0.00 sec)
6)修改主节点信息:
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='Yan+123kou' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.08 sec)
7)下载全同步配置服务,激活复制服务,开启组同步:
mysql> INSTALL PLUGIN group_replication SONAME 'group_replication.so';
Query OK, 0 rows affected (0.04 sec)
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 (6.75 sec)
8)server2也已经添加进去了:
mysql> SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
| group_replication_applier | 65b6e846-ef54-11ea-baf8-5254000fd593 | server1.example.com | 3306 | ONLINE |
| group_replication_applier | 6c4bde80-ef57-11ea-943a-525400019149 | server2.example.com | 3306 | RECOVERING |
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
2 rows in set (0.00 sec)
2.3 配置server3
1)server2将自己的配置文件发送给server3,server3进行修改:
[root@server1 mysql]# scp /etc/my.cnf root@172.25.5.10:/etc/
root@172.25.5.10's password:
my.cnf
server_id=3
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="513e6d8e-ef42-11ea-8fe7-5254000fd593"
loose-group_replication_start_on_boot=off
loose-group_replication_local_address="172.25.5.10:33061"
loose-group_replication_group_seeds="172.25.5.11:33061,172.25.5.12:33061,172.25.5.10:33061"
loose-group_replication_bootstrap_group=off
loose-group_replication_ip_whitelist="127.0.0.1,172.25.5.0/24"
loose-group_replication_enforce_update_everywhere_checks=ON
loose-group_replication_single_primary_mode=OFF
2)启动mysql服务,修改root用户的密码:
[root@server3 mysql]# systemctl start mysqld
[root@server3 mysql]# cat /var/log/mysqld.log | grep password
2020-09-05T09:40:09.146500Z 1 [Note] A temporary password is generated for root@localhost: KWY.WLgaj7aa
[root@server3 mysql]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.24-log
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> alter user root@localhost identified by "Server+147";
Query OK, 0 rows affected (0.00 sec)
3)关闭二进制日志,建立从节点用户,再次开启二进制日志:
mysql> SET SQL_LOG_BIN=0;
Query OK, 0 rows affected (0.00 sec)
mysql> CREATE USER rpl_user@'%' IDENTIFIED BY 'Yan+123kou';
Query OK, 0 rows affected (0.00 sec)
mysql> GRANT REPLICATION SLAVE ON *.* TO rpl_user@'%';
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)
mysql> SET SQL_LOG_BIN=1;
Query OK, 0 rows affected (0.00 sec)
4)修改主节点信息:
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='Yan+123kou' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.08 sec)
5)下载全同步配置服务,激活复制服务,开启组同步:
mysql> INSTALL PLUGIN group_replication SONAME 'group_replication.so';
Query OK, 0 rows affected (0.04 sec)
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 (6.75 sec)
6)server3也已经添加进去了:
mysql> SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
| group_replication_applier | 65b6e846-ef54-11ea-baf8-5254000fd593 | server1.example.com | 3306 | ONLINE |
| group_replication_applier | 6c4bde80-ef57-11ea-943a-525400019149 | server2.example.com | 3306 | RECOVERING |
| group_replication_applier | c9973fad-ef5b-11ea-afa5-525400c4b8ec | server3.example.com | 3306 | RECOVERING |
+---------------------------+--------------------------------------+---------------------+-------------+--------------+
3 rows in set (0.00 sec)
这时在server1上写入的数据server2server3上都会出现,任意一个写得,其他两个都会出现。