yum install -y mariadb mariadb-server
systemctl start mariadb
mysql -uroot -e "grant all privileges on *.* to 'all'@'%' identified by 'xx';"

cat /etc/haproxy/conf.d/mysql.cfg 
global
    log         127.0.0.1 local2
    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     50
    user        haproxy
    group       haproxy
    daemon
    stats socket /var/lib/haproxy/stats
defaults
    mode                    http
    log                     global
    option                  httplog
    option                  dontlognull
    option                  http-server-close
    option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 3000
listen haproxy-stats
    bind *:9999
    stats enable
    stats hide-version
    stats uri     /haproxy?stats
    stats realm   "Haproxy Statistics"
    stats auth    admin:admin
    stats admin if TRUE
frontend main
    bind *:3366
    mode tcp
    log global
    use_backend mysql_servers
    
backend mysql_servers
    mode tcp
    balance roundrobin
    server node1 172.16.1.7:3306 check port 3306
    server node2 172.16.1.8:3306 check port 3306

client客户端测试
yum install -y mariadb
mysql -h10.0.0.200 -uall -p123456 -P3366