首先在介绍MySQL 主从时，我们来看看 DB-Engines 排行榜上四月数据库的变化，前三甲居然都有小幅度增长，相反增长迅猛的 PG 和 MongoDB 有所减少，一个月的增长趋势说明不了问题，下图是从 13 年开始的趋势图，Oracle 和 MySQL 渐渐趋平，学习了解 MySQL 还是很有必要的。下面开始进入正题。
（图源：http://db-engines.com/en/ranking）
主从复制的原理
MySQL的主从复制中主要有三个线程：master（binlog dump thread）、slave（I/O thread 、SQL thread），Master一条线程和Slave中的两条线程。
（1）master服务器将数据的改变记录二进制binlog日志，当master上的数据发生改变时，则将其改变写入二进制日志中；
（2）slave服务器会在一定时间间隔内对master二进制日志进行探测其是否发生改变，如果发生改变，则开始一个I/OThread请求master二进制事件
（3）同时主节点为每个I/O线程启动一个dump线程，用于向其发送二进制事件，并保存至从节点本地的中继日志中，从节点将启动SQL线程从中继日志中读取二进制日志，在本地重放，使得其数据和主节点的保持一致，最后I/OThread和SQLThread将进入睡眠状态，等待下一次被唤醒。
（图源 深入浅出 MySQL 数据库开发、优化与管理维护）
由于资源限制没有那么多机器，本次使用一台原先装过 Oracle 和 OGG 的主机构建一主两从的MySQL 环境，通过三个不同的端口 3306、3307、3308 加以区分。
一、系统准备
0、查看系统版本
cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.6 (Maipo)
1、关闭防火墙
systemctl stop firewalld.service或者systemctl stop firewalld
systemctl disable firewalld.service或者systemctl disable firewalld
systemctl status firewalld
2、关闭 selinux
getenforce
setenforce 0
vim /etc/selinux/config
SELINUX=disabled
[root@Ops-11gOGG ~]# systemctl status firewalld
? firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
Active: inactive (dead)
Docs: man:firewalld(1)
[root@Ops-11gOGG ~]# getenforce
Disabled
3、/etc/hosts解析
示例如下
192.168.77.86 Ops-11gOGG
4、配置 yum 源，安装依赖 rpm 包
yum -y groupinstall "DeveLopment tools"
yum -y install ncurses ncurses-devel openssl-devel bison gcc gcc-c++ make
5、清理系统环境
Linux7 版本的系统默认自带安装了MariaDB，需要先清理。
## 查询已安装的mariadb
rpm -qa |grep mariadb
或
yum list installed | grep mariadb
## 卸载mariadb包，文件名为上述命令查询出来的文件
rpm -e --nodeps mariadb-libs-5.5.60-1.el7_5.x86_64
yum -y remove mariadb-libs.x86_64
二、安装 MySQL8.0.28
0、创建实例所需目录
本手册中 3306 为一个实例，如部署多实例请按照下面目录结构创建目录
--root用户操作：
mkdir -p /mysql/data/mysql3306
mkdir -p /mysql/app/
mkdir -p /mysql/conf/
mkdir -p /mysql/data/mysql3306/data/
mkdir -p /mysql/data/mysql3306/pid/
mkdir -p /mysql/data/mysql3306/socket/
mkdir -p /mysql/data/mysql3306/log/
mkdir -p /mysql/data/mysql3306/binlog/
mkdir -p /mysql/data/mysql3306/relaylog/
mkdir -p /mysql/data/mysql3306/slowlog/
mkdir -p /mysql/data/mysql3306/tmp/
mkdir -p /mysql/data/mysql3307
mkdir -p /mysql/data/mysql3307/data/
mkdir -p /mysql/data/mysql3307/pid/
mkdir -p /mysql/data/mysql3307/socket/
mkdir -p /mysql/data/mysql3307/log/
mkdir -p /mysql/data/mysql3307/binlog/
mkdir -p /mysql/data/mysql3307/relaylog/
mkdir -p /mysql/data/mysql3307/slowlog/
mkdir -p /mysql/data/mysql3307/tmp/
mkdir -p /mysql/data/mysql3308
mkdir -p /mysql/data/mysql3308/data/
mkdir -p /mysql/data/mysql3308/pid/
mkdir -p /mysql/data/mysql3308/socket/
mkdir -p /mysql/data/mysql3308/log/
mkdir -p /mysql/data/mysql3308/binlog/
mkdir -p /mysql/data/mysql3308/relaylog/
mkdir -p /mysql/data/mysql3308/slowlog/
mkdir -p /mysql/data/mysql3308/tmp/
1、创建数据库用户和组
groupadd mysql
useradd -g mysql mysql
chown -R mysql:mysql /mysql
passwd mysql
2、上传解压安装包并重命名
如下链接，选择相关的版本和系统。
https://dev.mysql.com/downloads/mysql/8.0.html
MD5: 5be32f68d6859aace1eb61cea1d00bff
mysql用户操作：
cd /mysql/app
md5sum mysql-8.0.28-linux-glibc2.12-x86_64.tar.xz --检验 MD5 值和上面一样，说明包无损
tar xvf mysql-8.0.28-linux-glibc2.12-x86_64.tar.xz
mv mysql-8.0.28-linux-glibc2.12-x86_64 mysql8.0.28
3、配置mysql用户环境变量
vim ~/.bash_profile
MYSQL_HOME=/mysql/app/mysql8.0.28
PATH=$PATH:$HOME/.local/bin:$HOME/bin:$MYSQL_HOME/bin
source ~/.bash_profile
which mysql
4、创建参数文件
由于是二进制文件安装，数据库参数文件需要自己配置，以下是简单的参数配置。其他参数可依照个人需求添加。
vim my3306.cnf
[mysqld]
# basic settings #
server_id = 863306
basedir = /mysql/app/mysql8.0.28
datadir = /mysql/data/mysql3306/data/
socket = /mysql/data/mysql3306/socket/mysql3306.sock
pid_file = /mysql/data/mysql3306/pid/mysqld3306.pid
port = 3306
default-time_zone = '+8:00'
character_set_server = utf8mb4
explicit_defaults_for_timestamp = 1
autocommit = 1
transaction_isolation = READ-COMMITTED
secure_file_priv = "/mysql/data/mysql3306/tmp/"
max_allowed_packet = 64M
lower_case_table_names = 1
default_authentication_plugin = mysql_native_password
sql_mode = 'STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION'
# connection #
back_log = 500
interactive_timeout = 300
wait_timeout = 300
lock_wait_timeout = 300
max_user_connections = 800
skip_name_resolve = 1
max_connections = 3000
max_connect_errors = 1000
#table cache performance settings
#table_open_cache = 1024
#table_definition_cache = 1024
#table_open_cache_instances = 16
#session memory settings #
#read_buffer_size = 16M
#read_rnd_buffer_size = 32M
#sort_buffer_size = 32M
#tmp_table_size = 64M
#join_buffer_size = 128M
#thread_cache_size = 256
# log settings #
slow_query_log = ON
slow_query_log_file = /mysql/data/mysql3306/slowlog/slow3306.log
log_error = /mysql/data/mysql3306/log/mysqld3306.log
log_error_verbosity = 3
log_bin = /mysql/data/mysql3306/binlog/mysql_bin
log_bin_index = /mysql/data/mysql3306/binlog/mysql_binlog.index
# general_log_file = /data/mysql/mysql57_3306/generallog/general.log
log_queries_not_using_indexes = 1
log_slow_admin_statements = 1
#log_slow_slave_statements = 1
#expire_logs_days = 15
binlog_expire_logs_seconds = 2592000
long_query_time = 2
min_examined_row_limit = 100
log_throttle_queries_not_using_indexes = 1000
#log_bin_trust_function_creators = 1
log_slave_updates = 1
mysqlx_port = 33060
mysqlx_socket = /mysql/data/mysql3306/socket/mysqlx.sock
# innodb settings #
innodb_buffer_pool_size = 512M
#innodb_buffer_pool_instances = 16
innodb_log_buffer_size = 100M
innodb_buffer_pool_load_at_startup = 1
innodb_buffer_pool_dump_at_shutdown = 1
innodb_lru_scan_depth = 4096
innodb_lock_wait_timeout = 20
innodb_io_capacity = 5000
innodb_io_capacity_max = 10000
innodb_flush_method = O_DIRECT
innodb_log_file_size = 1G
innodb_log_files_in_group = 2
innodb_purge_threads = 4
innodb_thread_concurrency = 200
innodb_print_all_deadlocks = 1
innodb_strict_mode = 1
innodb_sort_buffer_size = 32M
innodb_write_io_threads = 16
innodb_read_io_threads = 16
innodb_file_per_table = 1
innodb_stats_persistent_sample_pages = 64
innodb_autoinc_lock_mode = 2
innodb_online_alter_log_max_size = 1G
innodb_open_files = 4096
innodb_buffer_pool_dump_pct = 25
innodb_page_cleaners = 16
innodb_undo_log_truncate = 1
innodb_max_undo_log_size = 2G
innodb_purge_rseg_truncate_frequency = 128
innodb_flush_log_at_trx_commit = 1
# replication settings #
master_info_repository = TABLE
relay_log_info_repository = TABLE
sync_binlog = 1
binlog_format = ROW
gtid_mode = ON
enforce_gtid_consistency = ON
relay_log_recovery = 1
relay_log = /mysql/data/mysql3306/relaylog/relay.log
relay_log_index = /mysql/data/mysql3306/relaylog/mysql_relay.index
slave_parallel_type = LOGICAL_CLOCK
slave_parallel_workers = 16
binlog_gtid_simple_recovery = 1
slave_preserve_commit_order = 1
binlog_rows_query_log_events = 1
slave_transaction_retries = 10
log_timestamps = system
report_host = 192.168.75.86
report_port = 3306
–report_host复制副本注册期间要报告给源库的复制副本的主机名或IP地址。此值显示在源服务器上显示副本的输出中。如果不希望复制副本向源注册，请将该值保留为未设置。
其他两节点参数文件my3307.cnf、my3308.cnf中将上述文件中的 3306 全部替换为 3307、3308 即可。
5、数据库初始化
mysql用户操作，注意同主机参数文件名my3306.cnf 各不相同，间隔约两分钟分别初始化三个 MySQL 实例。
mysqld --defaults-file=/mysql/conf/my3306.cnf --initialize --user=mysql --basedir=/mysql/app/mysql8.0.28 --datadir=/mysql/data/mysql3306/data
mysqld --defaults-file=/mysql/conf/my3307.cnf --initialize --user=mysql --basedir=/mysql/app/mysql8.0.28 --datadir=/mysql/data/mysql3307/data
mysqld --defaults-file=/mysql/conf/my3308.cnf --initialize --user=mysql --basedir=/mysql/app/mysql8.0.28 --datadir=/mysql/data/mysql3307/data
6、启动三个数据库实例
mysqld_safe --defaults-file=/mysql/conf/my3306.cnf --user=mysql &
mysqld_safe --defaults-file=/mysql/conf/my3307.cnf --user=mysql &
mysqld_safe --defaults-file=/mysql/conf/my3308.cnf --user=mysql &
--关闭数据库
mysqladmin -uroot -p -h 127.0.0.1 -P 3306 shutdown
7、查看初始化 root 密码并修改
more /mysql/data/mysql3306/log/mysqld3306.log|grep password
more /mysql/data/mysql3306/log/mysqld3307.log|grep password
more /mysql/data/mysql3306/log/mysqld3308.log|grep password
如下图所示，3306 端口 root@localhost密码为“GW*QXYwSs7;f”，初始化密码比较复杂，这里由于是测试环境，将其修改为“root”;
[mysql@Ops-11gOGG ~]$ mysql -uroot -p -P 3306 -S /mysql/data/mysql3306/socket/mysql3306.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.28
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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 'root';
Query OK, 0 rows affected (0.01 sec)
mysql> create user root@'%' identified by 'root';
Query OK, 0 rows affected (0.02 sec)
mysql> grant all privileges on *.* to root@'%' with grant option;
Query OK, 0 rows affected (0.00 sec)
其他两台也是如此，并创建远程 root 登录账号。
三、构建主从环境
1、主库 3306 创建复制账号 rep
create user rep@'%' identified by 'rep';
grant REPLICATION CLIENT,REPLICATION SLAVE on *.* to rep@'%';
我这里需要置空 gtid 信息。
reset master;
show master status;
快速构建主从
登录3307
mysql -uroot -p -P 3307 -S /mysql/data/mysql3307/socket/mysql3307.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 8.0.28 MySQL Community Server - GPL
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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>
change master to master_host='192.168.75.86',master_port=3306,master_user='rep',master_password='rep',master_auto_position=1;
show slave status\G
start slave;
show slave status\G
mysql> start slave;
Query OK, 0 rows affected, 1 warning (1.04 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for source to send event
Master_Host: 192.168.75.86
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql_bin.000002
Read_Master_Log_Pos: 1486
Relay_Log_File: relay.000002
Relay_Log_Pos: 373
Relay_Master_Log_File: mysql_bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1396
Last_Error: Coordinator stopped because there were error(s) in the worker(s). The most recent failure being: Worker 1 failed executing transaction '3ba436e0-aa7c-11ec-bba1-0050568a6bf6:2' at master log mysql_bin.000002, end_log_pos 730. See error log and/or performance_schema.replication_applier_status_by_worker table for more details about this failure or others, if any.
Skip_Counter: 0
Exec_Master_Log_Pos: 157
Relay_Log_Space: 1902
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 1396
Last_SQL_Error: Coordinator stopped because there were error(s) in the worker(s). The most recent failure being: Worker 1 failed executing transaction '3ba436e0-aa7c-11ec-bba1-0050568a6bf6:2' at master log mysql_bin.000002, end_log_pos 730. See error log and/or performance_schema.replication_applier_status_by_worker table for more details about this failure or others, if any.
Replicate_Ignore_Server_Ids:
Master_Server_Id: 863306
Master_UUID: 3ba436e0-aa7c-11ec-bba1-0050568a6bf6
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp: 220323 16:03:06
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: 3ba436e0-aa7c-11ec-bba1-0050568a6bf6:1-5
Executed_Gtid_Set: 3ba436e0-aa7c-11ec-bba1-0050568a6bf6:1
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
Master_public_key_path:
Get_master_public_key: 0
Network_Namespace:
1 row in set, 1 warning (0.01 sec)
修复问题
show master status;
stop slave;
reset slave all;
reset master;
登录3306
mysql -uroot -p -P 3306 -S /mysql/data/mysql3306/socket/mysql3306.sock
show master status;
reset master;
show master status;
重新构建主从
注意：从 MySQL 8.0.22 开始，START SLAVE、STOP SLAVE、SHOW SLAVE STATUS、SHOW SLAVE HOST、RESET SLAVE 均被弃用，取而代之的则是 start replica、stop replica、show replica status、show replicas 和 reset replica。 MySQL 8.0.23 版本开始，change replication source to 取代了以前一直使用的 change master to 命令。MySQL 8.0.26 版本开始，系统变量、参数等标识符中的 MASTER、SLAVE、MTS(multithreaded slave)将被 SOURCE、REPLICA 和 MTA(multithreaded applier) 取代。
登录3307
[mysql@Ops-11gOGG conf]$ mysql -uroot -p -P 3307 -S /mysql/data/mysql3307/socket/mysql3307.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 29
Server version: 8.0.28 MySQL Community Server - GPL
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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> change master to master_host='192.168.75.86',master_port=3306,master_user='rep',master_password='rep',master_auto_position=1;
Query OK, 0 rows affected, 8 warnings (0.03 sec)
mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.05 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for source to send event
Master_Host: 192.168.75.86
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql_bin.000001
Read_Master_Log_Pos: 157
Relay_Log_File: relay.000002
Relay_Log_Pos: 373
Relay_Master_Log_File: mysql_bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 157
Relay_Log_Space: 573
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 863306
Master_UUID: 3ba436e0-aa7c-11ec-bba1-0050568a6bf6
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Replica has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
Master_public_key_path:
Get_master_public_key: 0
Network_Namespace:
1 row in set, 1 warning (0.01 sec)
登录 3308
[mysql@Ops-11gOGG conf]$ mysql -uroot -p -P 3308 -S /mysql/data/mysql3308/socket/mysql3308.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.28 MySQL Community Server - GPL
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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>
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql_bin.000001 | 157 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> change master to master_host='192.168.75.86',master_port=3306,master_user='rep',master_password='rep',master_auto_position=1;
Query OK, 0 rows affected, 8 warnings (0.03 sec)
mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.35 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for source to send event
Master_Host: 192.168.75.86
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql_bin.000001
Read_Master_Log_Pos: 157
Relay_Log_File: relay.000002
Relay_Log_Pos: 373
Relay_Master_Log_File: mysql_bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 157
Relay_Log_Space: 573
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 863306
Master_UUID: 3ba436e0-aa7c-11ec-bba1-0050568a6bf6
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Replica has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
Master_public_key_path:
Get_master_public_key: 0
Network_Namespace:
1 row in set, 1 warning (0.01 sec)
登录主库 3306 查看
show slave hosts;
[mysql@Ops-11gOGG conf]$ mysql -uroot -p -P 3306 -S /mysql/data/mysql3306/socket/mysql3306.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 8.0.28 MySQL Community Server - GPL
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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> show slave hosts;
+-----------+-------------+------+-----------+--------------------------------------+
| Server_id | Host | Port | Master_id | Slave_UUID |
+-----------+-------------+------+-----------+--------------------------------------+
| 863308 | 192.168.75.86 | 3308 | 863306 | efeadd1c-aa7c-11ec-a0e3-0050568a6bf6 |
| 863307 | 192.168.75.86 | 3307 | 863306 | e0d081ae-aa7c-11ec-9b41-0050568a6bf6 |
+-----------+-------------+------+-----------+--------------------------------------+
2 rows in set, 1 warning (0.00 sec)
mysql> show processlist;
+----+-----------------+-------------------+------+------------------+------+-----------------------------------------------------------------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-----------------+-------------------+------+------------------+------+-----------------------------------------------------------------+------------------+
| 5 | event_scheduler | localhost | NULL | Daemon | 1467 | Waiting on empty queue | NULL |
| 11 | rep | 192.168.75.86:50360 | NULL | Binlog Dump GTID | 232 | Source has sent all binlog to replica; waiting for more updates | NULL |
| 12 | rep | 192.168.75.86:50420 | NULL | Binlog Dump GTID | 109 | Source has sent all binlog to replica; waiting for more updates | NULL |
| 13 | root | localhost | NULL | Query | 0 | init | show processlist |
+----+-----------------+-------------------+------+------------------+------+-----------------------------------------------------------------+------------------+
4 rows in set (0.00 sec)
两从库分别修改参数限制只读模式
show variables like '%read_only%';
set global read_only=1;
set global super_read_only=1;
[mysql@Ops-11gOGG conf]$ mysql -uroot -p -P 3308 -S /mysql/data/mysql3308/socket/mysql3308.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 28
Server version: 8.0.28 MySQL Community Server - GPL
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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> show master status;
+------------------+----------+--------------+------------------+------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql_bin.000001 | 544 | | | 3ba436e0-aa7c-11ec-bba1-0050568a6bf6:1-2 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row 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 |
+-----------------------+-------+
4 rows in set (0.02 sec)
mysql> set global read_only=1;
Query OK, 0 rows affected (0.00 sec)
mysql> set global super_read_only=1;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like '%read_only%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | ON |
| super_read_only | ON |
| transaction_read_only | OFF |
+-----------------------+-------+
4 rows in set (0.01 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql_bin.000001 | 544 | | | 3ba436e0-aa7c-11ec-bba1-0050568a6bf6:1-2 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)
————————————————————————————
公众号：JiekeXu DBA之路
墨天轮：https://www.modb.pro/u/4347
CSDN ：https://blog.csdn.net/JiekeXu
腾讯云：https://cloud.tencent.com/developer/user/5645107
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最后修改时间：2023-05-17 11:24:38
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