架構概述

MGR node1：192.168.222.76:3307

MGR node2：192.168.222.77:3307

MGR node3：192.168.222.78:3307

ProxySQL：192.168.222.75

一、數據庫節點安裝

1.1、數據庫服務器基礎配置

分別在3臺數據節點（192.168.222.76、77、78）上執行：

（1）設置hostname：

hostnamectl set-hostname mgr_node1 (node2/node3)

（2）編輯 /etc/hosts，新增host信息

192.168.222.76  mgr_node1
192.168.222.77  mgr_node2
192.168.222.78  mgr_node3

（3）關閉SELinux：setenforce 0

（4）修改ulimit值，vim /etc/security/limits.conf

* soft nofile 1024000
* hard nofile 1024000

1.2、數據庫節點初始化

1.2.1、數據庫服務依賴包

rpm -e mariadb-devel

yum install mysql-community-common

yum install mysql-community-libs

yum install mysql-community-devel

yum install mysql-community-libs-compat

yum install libaio

1.2.2、創建數據庫用戶

groupadd mysql

useradd -r -g mysql -s /bin/false mysql

1.2.3、解壓二進制文件

xz -d mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz

tar xvf mysql-8.0.20-linux-glibc2.12-x86_64.tar -C /usr/local/

ln -s mysql-8.0.20-linux-glibc2.12-x86_64 mysql3307

cd mysql3307

mkdir mysql-files

chown mysql:mysql mysql-files

chmod 750 mysql-files

1.2.4、配置文件中添加MGR信息

以第一節點爲例，MGR關鍵配置如下

server_id=2220763307
report_host='mgr_node1'
gtid_mode=ON
enforce_gtid_consistency=ON
binlog_format=row
binlog_checksum=NONE

disabled_storage_engines="MyISAM,BLACKHOLE,FEDERATED,ARCHIVE,MEMORY"
#兼容老版本客戶端
default_authentication_plugin=mysql_native_password

# 默認算法已經是XXHASH64，可以不配置
transaction_write_set_extraction=XXHASH64
loose-group_replication_group_name="aaaaaaaa-aaaa-aaaa-aaaaaaaaaaaaaaaa"
# 單主
loose-group_replication_single_primary_mode=ON
# 單主模式下，關閉該配置
loose-group_replication_enforce_update_everywhere_checks=OFF
# 不自動啓動group replication
loose-group_replication_start_on_boot=OFF
loose-group_replication_local_address= "192.168.222.76:33071"
loose-group_replication_group_seeds= "192.168.222.76:33071,192.168.222.77:33071,192.168.222.78.33071"
# 設立當前節點爲集羣引導節點時短暫開啓，默認OFF，可以不配置
loose-group_replication_bootstrap_group=OFF

運行uuidgen，生成的uuid填入：group_replication_group_name

1.2.5、初始化數據

./bin/mysqld --defaults-file=/usr/local/mysql3307/my.cnf --initialize-insecure --user=mysql

1.2.6、啓動第一節點

./bin/mysqld --defaults-file=/usr/local/mysql3307/my.cnf &

二、MGR第一節點配置

2.1、集羣同步賬號

CREATE USER 'mgr_repl'@'%' IDENTIFIED WITH mysql_native_password BY '123456';

# 集羣間同步數據用

GRANT REPLICATION SLAVE ON *.* TO 'mgr_repl'@'%';

2.2、安裝group replication插件

INSTALL PLUGIN group_replication SONAME 'group_replication.so';

CHANGE MASTER TO MASTER_USER='mgr_repl', MASTER_PASSWORD='123456' FOR CHANNEL 'group_replication_recovery';

FLUSH PRIVILEGES;

2.3、啓動group replication

set global group_replication_bootstrap_group=ON;

start group_replication;

set global group_replication_bootstrap_group=OFF;

確認集羣狀態：

root@testnode1 [14:38] > SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| CHANNEL_NAME              | MEMBER_ID                            | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| group_replication_applier | 3d35218d-94c5-11ea-b213-005056b8a4a4 | mgr_node1   |        3307 | ONLINE       | PRIMARY     | 8.0.20         |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
1 row in set (0.01 sec)

三、MGR其餘節點啓動

3.1、全量同步方式（適用於集羣中已有節點的binlog完整保留的情況）

新節點正常初始化後啓動，執行：

INSTALL PLUGIN group_replication SONAME 'group_replication.so';

（非必要，建議執行）INSTALL PLUGIN clone SONAME 'mysql_clone.so';

CHANGE MASTER TO MASTER_USER='mgr_repl', MASTER_PASSWORD='123456' FOR CHANNEL 'group_replication_recovery';

start group_replication;

查看集羣中節點：

root@testnode2 [18:04] > SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| CHANNEL_NAME              | MEMBER_ID                            | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| group_replication_applier | 3d35218d-94c5-11ea-b213-005056b8a4a4 | mgr_node1   |        3307 | ONLINE       | PRIMARY     | 8.0.20         |
| group_replication_applier | 5da974a5-94f3-11ea-a178-005056b8c7db | mgr_node2   |        3307 | ONLINE       | SECONDARY   | 8.0.20         |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
2 rows in set (0.01 sec)

3.2、clone plugin方式（適用於集羣中已有節點的binlog做過清理的情況）

名詞解釋：Donor節點（集羣中已有節點） = > Recipient節點（欲加入集羣的節點）

3.2.1、備份插件安裝

首先，在donor節點檢查是否已安裝mysql_clone插件：

show plugins;

INSTALL PLUGIN clone SONAME 'mysql_clone.so';

然後，新節點正常初始化後啓動，安裝 group_replication 和 mysql_clone 插件：

INSTALL PLUGIN group_replication SONAME 'group_replication.so';

INSTALL PLUGIN clone SONAME 'mysql_clone.so';

recipient節點的group replication插件需要在克隆前就確保已安裝，否則啓動克隆時報錯如下：

ERROR 3870 (HY000): Clone Donor plugin group_replication is not active in Recipient.

3.2.2、Donor節點建立遠程備份賬號

遠程備份賬號權限：BACKUP_ADMIN

CREATE USER 'clone_user'@'%' IDENTIFIED BY '123456';

GRANT BACKUP_ADMIN on *.* to 'clone_user'@'%';

flush privileges;

3.2.3、Donor本地備份試驗

來到donor節點

# cd /data/

# mkdir clone_dir

# chown -R mysql:mysql clone_dir

mysql > clone local data directory = '/data/clone_dir/20200513';

備份進度可以通過如下sql查看：

root@testnode1 [21:59] > SELECT STAGE, STATE, END_TIME FROM performance_schema.clone_progress;
+-----------+-------------+----------------------------+
| STAGE     | STATE       | END_TIME                   |
+-----------+-------------+----------------------------+
| DROP DATA | Completed   | 2020-05-13 21:48:34.584910 |
| FILE COPY | Completed   | 2020-05-13 21:48:40.907383 |
| PAGE COPY | Completed   | 2020-05-13 21:48:41.113312 |
| REDO COPY | Completed   | 2020-05-13 21:48:41.315660 |
| FILE SYNC | Completed   | 2020-05-13 21:48:51.580895 |
| RESTART   | Not Started | NULL                       |
| RECOVERY  | Not Started | NULL                       |
+-----------+-------------+----------------------------+
7 rows in set (0.00 sec)

Tips：備份的文件配合一份新的配置文件，就可以在本地快速引導一套新的mysql實例

注意修改以下配置項，避免衝突：

server_id=2220783317
report_host='mgr_node4'
port = 3317
mysqlx-port=33170
datadir = /tmp/clone_dir/20200514
loose-group_replication_local_address= "192.168.222.78:33171"
loose-group_replication_group_seeds= "192.168.222.76:33071,192.168.222.77:33071,192.168.222.78.33071,192.168.222.78:33171"

root@testnode3 [15:17] > SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| CHANNEL_NAME              | MEMBER_ID                            | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| group_replication_applier | 3d35218d-94c5-11ea-b213-005056b8a4a4 | mgr_node1   |        3307 | ONLINE       | PRIMARY     | 8.0.20         |
| group_replication_applier | 5da974a5-94f3-11ea-a178-005056b8c7db | mgr_node2   |        3307 | ONLINE       | SECONDARY   | 8.0.20         |
| group_replication_applier | a553c26f-95b2-11ea-b31e-005056b854d7 | mgr_node4   |        3317 | ONLINE       | SECONDARY   | 8.0.20         |
| group_replication_applier | f1776459-958f-11ea-8dec-005056b854d7 | mgr_node3   |        3307 | ONLINE       | SECONDARY   | 8.0.20         |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
4 rows in set (0.00 sec)

3.2.4、Recipient節點遠程獲取克隆

step1、來到recipient節點，使用至少權限爲CLONE_ADMIN的賬號登錄（注：CLONE_ADMIN包含了BACKUP_ADMIN、SHUTDOWN權限）

step2、指向Donor節點

SET GLOBAL clone_valid_donor_list = '192.168.222.76:3307';

step3、填入Donor節點上的備份賬號

CLONE INSTANCE FROM 'clone_user'@'192.168.222.76':3307 IDENTIFIED BY '123456';

step4、克隆結束後，根據原先recipient節點的啓動方式執行關閉或自動重啓新節點。

Tips: 若以mysqld方式啓動，克隆完成後會有如下報錯，屬於正常現象（目前僅mysqld_safe方式支持自動重啓）：

ERROR 3707 (HY000): Restart server failed (mysqld is not managed by supervisor process)

3.2.5、啓動recipient節點(mysqld)

cd /usr/local/mysql3307

./bin/mysqld --defaults-file=/usr/local/mysql3307/my.cnf &

3.2.6、加入MGR集羣

CHANGE MASTER TO MASTER_USER='mgr_repl', MASTER_PASSWORD='123456' FOR CHANNEL 'group_replication_recovery';

start group_replication;

3.3、恢復xtrabackup備份方式（適用於集羣中已有節點的binlog做過清理的情況）

由於8.0.20的redo log格式有調整。xtrabackup-8.0.11基於8.0.18開發，故暫無法使用。官方回覆如下：

更新：Percona XtraBackup 8.0.12版本已支持MySQL 8.0.20

四、ProxySQL

4.1、安裝

如下地址下載rpm包，安裝

https://github.com/sysown/proxysql/releases

systemctl start proxysql

默認用戶名、密碼：admin:admin

mysql -u admin -padmin -h 127.0.0.1 -P6032 --prompt='Admin> '

4.2、修改ProxySQL基礎配置

Admin> use main

4.2.1、修改proxysql的admin密碼

Admin> update global_variables set variable_value = 'admin:adminpasswd' where variable_name = 'admin-admin_credentials';
Admin> LOAD ADMIN VARIABLES TO RUNTIME;
Admin> SAVE ADMIN VARIABLES TO DISK;

4.2.2、修改默認字符集utf8爲utf8mb4

set mysql-default_charset='utf8mb4';
set mysql-default_collation_connection='utf8mb4_general_ci';
set mysql-max_allowed_packet=67108864; #對應後端數據庫max_allowed_packet
#set mysql-ping_interval_server_msec=60000;       #sleep會話保持時長120s
set mysql-max_connections=10000;               #ProxySQL能處理前端請求的最大連接數
set mysql-server_version='8.0.20';               #proxysql響應給客戶端的MySQL版本號
set mysql-set_query_lock_on_hostgroup=0; #set語法兼容

Tips：避免如下報錯：
9006 - ProxySQL Error: connection is locked to hostgroup 10 but trying to reach hostgroup 30
https://github.com/sysown/proxysql/issues/2202

LOAD MYSQL VARIABLES TO RUNTIME;
SAVE MYSQL VARIABLES TO DISK;

4.2.3、定義寫、備寫、讀、離線組id

Admin> insert into mysql_group_replication_hostgroups(writer_hostgroup,backup_writer_hostgroup,reader_hostgroup, offline_hostgroup,active,max_writers,writer_is_also_reader)
values (10,20,30,40,1,1,1);

Tips:
Another similar option is currently being implemented in ProxySQL 2.0.9 for the transactions_behind check. See below:
mysql-monitor_groupreplication_max_transactions_behind
Currently, if group replication max_transactions_behind exceeds the threshold once, the node is evicted from the cluster.
The upcoming 2.0.9 release features another additional variable which will define a count for such checks so that max_transactions_behind would have to fail more than once (x number of times) before eviction.
mysql-monitor_groupreplication_max_transactions_behind_count默認3

將配置生效並存儲：
Admin> load mysql servers to runtime;
Admin> save mysql servers to disk;

確認已生效：
Admin> select * from runtime_mysql_group_replication_hostgroups;
+------------------+-------------------------+------------------+-------------------+--------+-------------+-----------------------+-------------------------+---------+
| writer_hostgroup | backup_writer_hostgroup | reader_hostgroup | offline_hostgroup | active | max_writers | writer_is_also_reader | max_transactions_behind | comment |
+------------------+-------------------------+------------------+-------------------+--------+-------------+-----------------------+-------------------------+---------+
| 10 | 20 | 30 | 40 | 1 | 1 | 0 | 100 | NULL |
+------------------+-------------------------+------------------+-------------------+--------+-------------+-----------------------+-------------------------+---------+
1 row in set (0.00 sec)

4.2.4、定義後端數據庫

Admin> insert into mysql_servers(hostgroup_id,hostname,port,max_connections) values(10,"192.168.222.76",3307,5000);
Admin> insert into mysql_servers(hostgroup_id,hostname,port,max_connections) values(30,"192.168.222.77",3307,5000);
Admin> insert into mysql_servers(hostgroup_id,hostname,port,max_connections) values(30,"192.168.222.78",3307,5000);

將配置生效並存儲：
Admin> load mysql servers to runtime;
Admin> save mysql servers to disk;

確認已生效：
select * from runtime_mysql_servers;
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+
| hostgroup_id | hostname | port | gtid_port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment |
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+
| 10 | 192.168.222.76 | 3307 | 0 | ONLINE | 1 | 0 | 5000 | 0 | 0 | 0 | |
| 30 | 192.168.222.78 | 3307 | 0 | ONLINE | 1 | 0 | 5000 | 0 | 0 | 0 | |
| 30 | 192.168.222.77 | 3307 | 0 | ONLINE | 1 | 0 | 5000 | 0 | 0 | 0 | |
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+
3 rows in set (0.00 sec)

4.2.5、配置監控賬號

在後端DB執行
需要在後端DB添加如下監控視圖：（來源https://github.com/lefred/mysql_gr_routing_check/blob/master/addition_to_sys.sql）

USE sys;
DELIMITER $$

CREATE FUNCTION my_id() RETURNS TEXT(36) DETERMINISTIC NO SQL RETURN (SELECT @@global.server_uuid as my_id);$$

CREATE FUNCTION gr_member_in_primary_partition()
    RETURNS VARCHAR(3)
    DETERMINISTIC
    BEGIN
      RETURN (SELECT IF( MEMBER_STATE='ONLINE' AND ((SELECT COUNT(*) FROM
    performance_schema.replication_group_members WHERE MEMBER_STATE NOT IN ('ONLINE', 'RECOVERING')) >=
    ((SELECT COUNT(*) FROM performance_schema.replication_group_members)/2) = 0),
    'YES', 'NO' ) FROM performance_schema.replication_group_members JOIN
    performance_schema.replication_group_member_stats USING(member_id) where member_id=my_id());
END$$

CREATE VIEW gr_member_routing_candidate_status AS SELECT
sys.gr_member_in_primary_partition() as viable_candidate,
IF( (SELECT (SELECT GROUP_CONCAT(variable_value) FROM
performance_schema.global_variables WHERE variable_name IN ('read_only',
'super_read_only')) != 'OFF,OFF'), 'YES', 'NO') as read_only,
Count_Transactions_Remote_In_Applier_Queue as transactions_behind, Count_Transactions_in_queue as 'transactions_to_cert' 
from performance_schema.replication_group_member_stats where member_id=my_id();$$

DELIMITER ;

create user 'proxysql_monitor'@'%' identified by '123456';
grant select on sys.gr_member_routing_candidate_status to 'proxysql_monitor'@'%';
flush privileges;

在proxysql中錄入監控賬號信息：
Admin> UPDATE global_variables SET variable_value='proxysql_monitor' WHERE variable_name='mysql-monitor_username';
Admin> UPDATE global_variables SET variable_value='123456' WHERE variable_name='mysql-monitor_password';

縮短監控巡檢週期到2秒（##需與官方文檔覈對##）
（默認60000、10000、1500）：
UPDATE global_variables SET variable_value='2000'
WHERE variable_name IN ('mysql-monitor_connect_interval','mysql-monitor_ping_interval','mysql-monitor_read_only_interval');

遇到： MySQL_Session.cpp:1454:handler_again___status_PINGING_SERVER(): [ERROR] Detected a broken connection during ping on (10,10.10.7.53,3306) , FD (Conn:2339 , MyDS:2339) : 2013, Lost connection to MySQL server during query
可適當調大mysql-monitor_ping_interval:2000=>5000

運行如下命令進行校對：
SELECT * FROM global_variables WHERE variable_name LIKE 'mysql-monitor_%';
無誤後，將配置生效並存儲
Admin> LOAD MYSQL VARIABLES TO RUNTIME;
Admin> SAVE MYSQL VARIABLES TO DISK;

確認監控是否可用（未配置前，是access denied狀態）
Admin> SELECT * FROM monitor.mysql_server_connect_log ORDER BY time_start_us DESC LIMIT 10;
+----------------+------+------------------+-------------------------+-------------------------------------------------------------------------+
| hostname | port | time_start_us | connect_success_time_us | connect_error |
+----------------+------+------------------+-------------------------+-------------------------------------------------------------------------+
| 192.168.222.78 | 3307 | 1589546175511459 | 1723 | NULL |
| 192.168.222.77 | 3307 | 1589546175088734 | 1492 | NULL |
| 192.168.222.76 | 3307 | 1589546174666010 | 842 | NULL |
| 192.168.222.76 | 3307 | 1589546115653773 | 1281 | NULL |
| 192.168.222.77 | 3307 | 1589546115160901 | 1767 | NULL |
| 192.168.222.78 | 3307 | 1589546114667025 | 1431 | NULL |
| 192.168.222.78 | 3307 | 1589546090462462 | 0 | Access denied for user 'monitor'@'192.168.222.76' (using password: YES) |
| 192.168.222.76 | 3307 | 1589546089762699 | 0 | Access denied for user 'monitor'@'192.168.222.76' (using password: YES) |
| 192.168.222.77 | 3307 | 1589546089063100 | 0 | Access denied for user 'monitor'@'192.168.222.76' (using password: YES) |
| 192.168.222.77 | 3307 | 1589546030519571 | 0 | Access denied for user 'monitor'@'192.168.222.76' (using password: YES) |
+----------------+------+------------------+-------------------------+-------------------------------------------------------------------------+
10 rows in set (0.00 sec)

Admin> SELECT * FROM monitor.mysql_server_ping_log ORDER BY time_start_us DESC LIMIT 10;

4.2.6、配置簡單讀寫分離規則（僅測試用）

insert into mysql_query_rules(rule_id,active,match_digest,destination_hostgroup,apply) VALUES (101,1,"^SELECT .* FOR UPDATE$",10,1),(102,1,"^SELECT",30,1);

將配置生效並存儲：
load mysql query rules to runtime;
save mysql query rules to disk;

4.2.7、配置應用賬號

ProxySQL中配置：
insert into mysql_users(username,password,default_hostgroup) values('proxydb','proxydb',10);
LOAD MYSQL USERS TO RUNTIME;

load to runtime（memory=>runtime）時，會將runtime層的密碼自動加密（admin-hash_passwords默認ON）：
複測：SELECT username,password FROM runtime_mysql_users;

引用runtime層的加密密碼到memory層：
SAVE MYSQL USERS FROM RUNTIME;
複測：SELECT username,password FROM mysql_users;

引用memory層的加密密碼到disk層：
SAVE MYSQL USERS TO DISK;

後端DB配置：
create user 'proxydb'@'%' identified by 'proxydb';
grant XXX on *.* to 'proxydb'@'%';

通過ProxySQL的IP和P6033端口就能訪問了，自動讀寫分離

注：用begin顯示開始的事務，默認直接走寫節點

附1：cnf文件備份方法，用於傳遞到備用proxysql上
how to copy runtime configuration to another ProxySQL server?
SELECT CONFIG INTO OUTFILE /tmp/f1;
alias：SAVE CONFIG TO FILE /tmp/f2;

備用proxysql配置生效：
法一、
先刪除/var/lib/proxysql/proxysql.db，
再覆蓋備份文件到/etc/proxysql.cnf，修改權限爲root:proxysql
重啓備用proxysql

附2：
sysbench --report-interval=5 --num-threads=4 --num-requests=0 --max-time=20 --test=tests/db/oltp.lua --mysql-user='msandbox' --mysql-password='msandbox' --oltp-table-size=10000 --mysql-host=127.0.0.1 --mysql-port=6033 run
sysbench --num-threads=4 --max-requests=0 --max-time=20 --test=tests/db/oltp.lua --mysql-user='msandbox' --mysql-password='msandbox' --oltp-table-size=10000 --mysql-host=127.0.0.1 --mysql-port=6033 --db-ps-mode=disable run

五、ProxySQL Cluster配置

排版待編輯

已有節點完成配置後
ProxySQL Cluster信息配置
insert into proxysql_servers(hostname,port) values('10.10.7.51',6032),('10.10.7.52',6032);
load proxysql servers to runtime;
save proxysql servers to disk;

配置用於實例間通訊的賬號(;前爲本地登錄賬號，;後爲實例間同步端口)
Admin> update global_variables set variable_value = 'admin:13&3biYvWHQ7;proxysql_cluster:17yFhXm62$zH' where variable_name = 'admin-admin_credentials';

Admin> update global_variables set variable_value = 'proxysql_cluster' where variable_name = 'admin-cluster_username';
Admin> update global_variables set variable_value = '17yFhXm62$zH' where variable_name = 'admin-cluster_password';

SELECT * FROM global_variables WHERE variable_name LIKE 'admin-cluster_%';
確認無誤後：
Admin> LOAD ADMIN VARIABLES TO RUNTIME;
Admin> SAVE ADMIN VARIABLES TO DISK;

安裝新節點並啓動：
sudo systemctl start proxysql

# 登錄新ProxySQL節點，錄入以下cluster信息（sudo tail -f /var/lib/proxysql/proxysql.log觀察老節點輸出）
Admin> update global_variables set variable_value = 'admin:13&3biYvWHQ7;proxysql_cluster:17yFhXm62$zH' where variable_name = 'admin-admin_credentials';
Admin> update global_variables set variable_value = 'proxysql_cluster' where variable_name = 'admin-cluster_username';
Admin> update global_variables set variable_value = '17yFhXm62$zH' where variable_name = 'admin-cluster_password';

Admin> insert into proxysql_servers(hostname,port) values('10.10.7.51',6032),('10.10.7.52',6032);

Admin> load admin variables to runtime;
Admin> save admin variables to disk;

Admin> load proxysql servers to runtime;
Admin> save proxysql servers to disk;

目前，已確認以下值不會同步，需手動設置：
set mysql-default_charset='utf8mb4';
set mysql-default_collation_connection='utf8mb4_general_ci';
set mysql-max_connections=10000; #ProxySQL能處理前端請求的最大連接數
set mysql-server_version='8.0.20'; #proxysql響應給客戶端的MySQL版本號
set mysql-set_query_lock_on_hostgroup=0; #set語法兼容
LOAD MYSQL VARIABLES TO RUNTIME;
SAVE MYSQL VARIABLES TO DISK;

參考文檔：

MySQL 8.0 Reference Manual: 18.2.1 Deploying Group Replication in Single-Primary Mode

MySQL8.0新特性之clone

https://proxysql.com/documentation/ProxySQL-Configuration/

https://proxysql.com/documentation/proxysql-read-write-split-howto/

https://www.colabug.com/2019/1224/6764189/

MGR 8.0 + ProxySQL 2.0 部署實錄

架構概述

一、數據庫節點安裝

1.1、數據庫服務器基礎配置

1.2、數據庫節點初始化

1.2.1、數據庫服務依賴包

1.2.2、創建數據庫用戶

1.2.3、解壓二進制文件

1.2.4、配置文件中添加MGR信息

1.2.5、初始化數據

1.2.6、啓動第一節點

二、MGR第一節點配置

2.1、集羣同步賬號

2.2、安裝group replication插件

2.3、啓動group replication

三、MGR其餘節點啓動

3.1、全量同步方式（適用於集羣中已有節點的binlog完整保留的情況）

3.2、clone plugin方式（適用於集羣中已有節點的binlog做過清理的情況）

3.2.1、備份插件安裝

3.2.2、Donor節點建立遠程備份賬號

3.2.3、Donor本地備份試驗

3.2.4、Recipient節點遠程獲取克隆

3.2.5、啓動recipient節點(mysqld)

3.2.6、加入MGR集羣

3.3、恢復xtrabackup備份方式（適用於集羣中已有節點的binlog做過清理的情況）

四、ProxySQL

4.1、安裝

4.2、修改ProxySQL基礎配置

4.2.1、修改proxysql的admin密碼

4.2.2、修改默認字符集utf8爲utf8mb4

4.2.3、定義寫、備寫、讀、離線組id

4.2.4、定義後端數據庫

4.2.5、配置監控賬號

4.2.6、配置簡單讀寫分離規則（僅測試用）

4.2.7、配置應用賬號

五、ProxySQL Cluster配置