使用 HAProxy 进行 MySQL 负载均衡

本章教程主要记录如何用HAProxy 实现MySQL负载均衡配置。

一、安装haproxy

在 Ubuntu/Debian 上：

sudo apt-get update
sudo apt-get install haproxy

在 CentOS/RHEL 上：

sudo yum install haproxy

二、配置haproxy

编辑 HAProxy 配置文件（通常位于 /etc/haproxy/haproxy.cfg）。

#---------------------------------------------------------------------
# Example configuration for a possible web application.  See the
# full configuration options online.
#
#   https://www.haproxy.org/download/1.8/doc/configuration.txt
#
#---------------------------------------------------------------------

#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
    log         127.0.0.1 local2

    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

    # turn on stats unix socket
    stats socket /var/lib/haproxy/stats

    # utilize system-wide crypto-policies
    ssl-default-bind-ciphers PROFILE=SYSTEM
    ssl-default-server-ciphers PROFILE=SYSTEM

#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
    mode                    tcp
    log                     global
    option                  tcplog
    option                  dontlognull
    option                  redispatch
    retries                 3
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    maxconn                 3000

#---------------------------------------------------------------------
# MySQL frontend and backend configuration
#---------------------------------------------------------------------
frontend mysql_frontend
    bind *:3308
    default_backend mysql_backend

backend mysql_backend
    balance roundrobin
    server mysql1 172.19.0.2:3306 check
    server mysql2 172.19.0.3:3306 check

三、启动/重启/停止haproxy

1、启动haproxy

sudo systemctl start haproxy

2、重启haproxy

sudo systemctl restart haproxy

3、停止haproxy

sudo systemctl restart haproxy