# 开机自启
systemctl enable haproxy
# 启动
systemctl start haproxy
# 停止
systemctl stop haproxy
# 重启（修改配置后必执行）
systemctl restart haproxy
# 查看状态
systemctl status haproxy
# 配置语法校验（修改配置前必检测，避免服务起不来）
haproxy -c -f /etc/haproxy/haproxy.cfg

HAProxy核心配置文件详解

配置分四大块：global → defaults → frontend → backend

/etc/haproxy/haproxy.cfg

七层HTTP负载均衡

# ====================== 1. 全局配置 global ======================
global
    log         /dev/log    local0 info
    log         /dev/log    local0 notice
    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     40000        # 全局最大并发连接
    user        haproxy
    group       haproxy
    daemon                   # 后台守护进程运行
    stats socket /var/lib/haproxy/stats level admin  # 本地管理sock

# ====================== 2. 默认模板 defaults ======================
defaults
    mode                    http       # 七层http，四层改为 tcp
    log                     global
    option                  httplog    # 打印完整http日志
    option                  dontlognull
    option                  http-server-close
    option                  forwardfor # 传递真实客户端IP X-Forwarded-For
    option                  redispatch
    retries                 3          # 失败重试3次
    timeout connect         10s
    timeout client          30s
    timeout server          30s

# ====================== 3. 前端 frontend 接收用户请求 ======================
frontend http_front
    bind *:80                     # 监听本机80端口
    default_backend http_back     # 默认转发到后端集群
    # 监控页面配置 访问 http://服务器IP/haproxy-stats
    stats enable
    stats uri /haproxy-stats
    stats auth admin:123456       # 监控账号密码
    stats refresh 5s

# ====================== 4. 后端 backend 真实业务节点 ======================
backend http_back
    balance roundrobin            # 负载算法：轮询
    # 健康检查：每隔2秒探测，连续3次down标记故障，2次恢复上线
    server web01 192.168.1.10:80 check inter 2000 fall 3 rise 2 weight 1
    server web02 192.168.1.11:80 check inter 2000 fall 3 rise 2 weight 1

四层TCP代理示例

global
    maxconn 50000
    user haproxy
    group haproxy
    daemon

defaults
    mode tcp
    timeout connect 10s
    timeout client 60s
    timeout server 60s

# MySQL四层TCP代理
listen mysql_tcp_proxy
    bind *:3307
    balance leastconn
    server db-node1 192.168.0.20:3306 check inter 3000 fall 2 rise 2
    server db-node2 192.168.0.20:3306 check inter 3000 fall 2 rise 2

# 监控面板单独配置完整http参数，解决503
listen haproxy_stats
    bind *:8081
    mode http
    timeout connect 5s
    timeout client 30s
    timeout server 30s
    stats enable
    stats uri /stats
    stats auth admin:123456
    stats refresh 5s

针对四层

将上面四层tcp配置直接复制
haproxy -c -f /etc/haproxy/haproxy.cfg
systemctl restart haproxy

验证访问

http://192.168.0.20:8081/stats (默认admin/123456)

HAProxy配置mqtt端口

# mqtt 四层TCP代理
listen maqtt_tcp_proxy
    bind *:1889
    balance leastconn
    server node1-26 192.168.0.26:1889 check inter 3000 fall 2 rise 2
    server node2-3 192.168.0.3:1889 check inter 3000 fall 2 rise 2

HAProxy负载规则

balance leastconn 最少连接
roundrobin 轮询系统默认
source 源IP哈希同一个客户端IP永远固定分到同一台后端
uri/url_param 按请求 URL 哈希，TCP 模式不生效

测试案例，绑定ip后端挂了重启，可以自动切换

listen mqtt_tcp_proxy
    bind *:1889
    balance source
    hash-type consistent
    stick-table type ip size 200k expire 300s  # 5分钟过期
    stick on src
    server node1-26 192.168.0.26:1889 check inter 5000 fall 3 rise 2
    server node2-3 192.168.0.3:1889 check inter 5000 fall 3 rise 2