安裝環境：
OS CentOS 7.6
Mysql 8.0.26
同步方式：基於mysql binlog機制來實現主從數據庫邏輯同步。
1.Mysql 源碼安裝
1.1 卸載系統里面的mariadb
rpm -qa|grep mariadb
rpm -e --nodeps mariadb-libs-5.5.60-1.el7_5.x86_64
1.2 安裝基礎軟件包
yum -y install libaio ncurses-devel
1.3 解壓安裝包
cd /usr/local
tar zxvf /media/mysql-8.0.26-el7-x86_64.tar.gz
ln -s mysql-8.0.26-el7-x86_64 mysql
1.4 增加mysql系統用戶
useradd -r -s /bin/false mysql
cd /usr/local/mysql
mkdir mysql-files run log
touch log/mysqld.log
chown -R mysql:mysql /usr/local/mysql /usr/local/mysql-8.0.26-el7-x86_64 /data
chmod 750 mysql-files
1.5 增加環境變量
vi /etc/profile
export PATH=$PATH:/usr/local/mysql/bin
sed -i '$a\export PATH=\$PATH:/usr/local/mysql/bin' /etc/profile
source /etc/profile
1.6 初始化mysql
bin/mysqld --initialize-insecure --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql --console --lower-case-table-names=1
記錄臨時密碼，方便后續修改管理員密碼。
使用--initialize生成隨機密碼，使用--initialize-insecure生成空密碼.
如果，需要開啟不區分表名大小寫，需要在初始化時加入--lower-case-table-names=1。
其中：
--user 指定用戶
--basedir 指定Mysql安裝目錄
--datadir 指定數據目錄
--console 控制台輸出初始化信息
--lower-case-table-names=1 不區分大小寫（Mysql 8.0默認為區分大小寫）
開啟ssl連接
bin/mysql_ssl_rsa_setup --datadir=/data/mysql
1.7 創建配置文件
touch /etc/my.cnf
vim /etc/my.cnf
[client] port = 3060 default-character-set=utf8 [mysqld] default-storage-engine=innodb innodb_file_per_table=1
innodb_flush_log_at_trx_commit=1 ##事物redolog直接持久化到磁盤 max_allowed_packet=16M character_set_server=utf8 port = 3060 max_connections=2000 init_connect='SET NAMES utf8' basedir=/usr/local/mysql datadir=/data/mysql socket=/tmp/mysql.sock log-error=/usr/local/mysql/log/mysqld.log pid-file=/usr/local/mysql/run/mysqld.pid #bin log server_id=100 log-bin=/usr/local/mysql/log/product-bin binlog-ignore-db=sys,information_schema,performance_schema #binlog-do-db = disabled binlog_format=ROW binlog_row_image=FULL
sync_binlog=1 ##事物的binlog持久化到磁盤 max_binlog_size = 200m ##binlog每個日志文件大小 binlog_cache_size = 4m ##binlog緩存大小 max_binlog_cache_size = 512m ##最大binlog緩存大小 binlog_expire_logs_seconds=518400 ##binlog保留6天，默認值為30天
slave-skip-errors=all skip-slave-start=1 relay_log=mysql-relay-bin #expire_logs_days=10 ##該參數，mysql8.0版本失效 #slow query log slow_query_log=1 slow_query_log_file=/usr/local/mysql/log/slow_query.log lower_case_table_names = 1 [mysqld_safe] lower_case_table_names = 1 log-error=/usr/local/mysql/log/mysqld.log pid-file=/usr/local/mysql/run/mysqld.pid
1.8 配置Mysql開機啟動
vi /etc/systemd/system/mysqld.service
[Unit]
Description=MySQL Server
Documentation=man:mysqld(8)
Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html
After=network.target
After=syslog.target
[Install]
WantedBy=multi-user.target
[Service]
User=mysql
Group=mysql
ExecStart=/usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf
LimitNOFILE = 5000
#添加到開機啟動
systemctl enable mysqld.service
systemctl start mysqld
systemctl status mysqld
systemctl stop mysqld
1.9 修改Mysql管理員密碼
alter user 'root'@'localhost' identified with mysql_native_password by 'Mysql#2021';
create user 'root'@'%' identified with mysql_native_password by 'Mysql#2021';
grant all privileges on *.* to 'root'@'%' with grant option;
flush privileges;
2 配置Mysql主從同步（基於binlog）
2.1 創建用於復制操作的用戶
mysql> CREATE USER 'repl'@'172.31.60.204' IDENTIFIED WITH mysql_native_password BY 'Repl#2021';
Query OK, 0 rows affected (0.01 sec)
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'172.31.60.204';
Query OK, 0 rows affected (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
2.2 查詢主節點狀態
mysql> flush tables with read lock; ##鎖表，生產環境中不讓進新的數據，方便定位同步位置。 mysql> SHOW MASTER STATUS; +---------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +---------------+----------+--------------+------------------+-------------------+ | binlog.000002 | 850 | | | | +---------------+----------+--------------+------------------+-------------------+ 1 row in set (0.00 sec) mysql> unlock tables; ##解鎖
2.3 從（Slave）節點上設置參數
2.3.1 my.cnf 參數修改
[mysqld]
server-id = 2 ##不能與主服務器一致
log-bin=/usr/local/mysql/log/product-bin
#replicate-do-db = disabled
replicate-ignore-db = mysql,sys,information_schema,performance_schema
2.3.2 從數據庫配置
mysql> CHANGE MASTER TO
MASTER_HOST='172.31.60.203',
MASTER_USER='repl',
MASTER_PASSWORD='Repl#2021',
master_port=3060,
MASTER_LOG_FILE='binlog.000002',
MASTER_LOG_POS=850;
2.3.3.查看主從同步狀態
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 172.31.60.203
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: binlog.000002
Read_Master_Log_Pos: 850
Relay_Log_File: iZvy201a8evxfqvyn9fjpdZ-relay-bin.000001
Relay_Log_Pos: 4
Relay_Master_Log_File: binlog.000002
Slave_IO_Running: No
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: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 850
Relay_Log_Space: 156
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: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 0
Master_UUID:
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:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
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)
ERROR:
No query specified
2.3.4 開啟主從同步。
mysql> start slave;
再查看主從同步狀態
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for source to send event
Master_Host: 172.31.60.203
Master_User: repl
Master_Port: 3060
Connect_Retry: 60
Master_Log_File: binlog.000002
Read_Master_Log_Pos: 850
Relay_Log_File: iZvy201a8evxfqvyn9fjpdZ-relay-bin.000002
Relay_Log_Pos: 321
Relay_Master_Log_File: binlog.000002
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: 850
Relay_Log_Space: 548
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: 1
Master_UUID: 851839f0-eb7c-11eb-bfaa-00163e000e71
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: 0
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 (0.00 sec)
ERROR:
No query specified
查看下面兩項值均為Yes，即表示設置從服務器成功。
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
主從庫同步延遲查看：
Seconds_Behind_Master: 0
2.3.5 設置備庫為只讀：
mysql>set global read_only=1;
只讀狀態查看：
mysql> show global variables like "%read_only%"; +-----------------------+-------+ | Variable_name | Value | +-----------------------+-------+ | innodb_read_only | OFF | | read_only | ON | | super_read_only | OFF | | transaction_read_only | OFF | +-----------------------+-------+ 4 rows in set (0.01 sec)
從庫只讀狀態說明：
1） read_only=1只讀模式，salve仍然會讀取master上的日志，並且在slave庫中應用日志，保證主從數據庫同步一致；
2） read_only=1只讀模式，可以限定普通用戶進行數據修改的操作，但不會限定具有super權限的用戶的數據修改操作；
3） 如果要限定具有super權限的用戶也不能進行讀寫操作，就需要給所有的表加讀鎖的命令 “flush tables with read lock;”，不過這樣的話，雖然slave仍然會從master讀取到binlog日志，但是不能應用日志，與master數據不同步。
3.主備同步測試
Mysql主從同步配置完成。