Nginx中多种负载均衡策略配置的实战指南_Linux

前言

在当今高并发、大流量的互联网应用中，单台服务器往往难以承受巨大的访问压力。负载均衡作为解决这一问题的关键技术，能够将请求分发到多台服务器上，实现系统的高可用性和高性能。

nginx作为业界领先的web服务器和反向代理服务器，其负载均衡功能强大且配置灵活，被广泛应用于各大互联网公司。本文将深入探讨nginx负载均衡的各种策略和配置方法，通过实际案例帮助你掌握负载均衡的核心技能。

一、负载均衡基础概念

1.1 什么是负载均衡

负载均衡（load balancing）是一种将网络请求分配到多个服务器的技术，主要目的是：

核心目标：

高可用性：避免单点故障，提高系统可靠性
高性能：分散请求压力，提升系统处理能力
可扩展性：支持水平扩展，便于系统扩容
灵活性：支持动态调整和灰度发布

工作原理：

客户端 → 负载均衡器 → 后端服务器集群
↓
服务器1
服务器2
服务器3

1.2 负载均衡类型

硬件负载均衡

f5 big-ip：企业级硬件负载均衡器
a10：高性能负载均衡设备
citrix netscaler：应用交付控制器

优点：

性能强大，处理能力高
功能完善，支持复杂算法
稳定性好，可靠性高

缺点：

价格昂贵，成本高
配置复杂，需要专业维护
扩展性差，升级困难

软件负载均衡

nginx：高性能web服务器和反向代理
haproxy：高可用性负载均衡器
lvs：linux虚拟服务器
apache mod_proxy_balancer：apache模块

优点：

成本低廉，开源免费
配置灵活，易于扩展
社区活跃，支持丰富

缺点：

性能相对硬件较低
功能相对简单
需要自己维护高可用

1.3 nginx负载均衡优势

技术优势：

高性能：基于事件驱动架构，支持数万并发连接
高可用性：支持健康检查和故障转移
灵活性：支持多种负载均衡算法
扩展性：支持第三方模块扩展

功能优势：

七层负载均衡：支持http/https协议
四层负载均衡：支持tcp/udp协议
ssl终止：支持ssl证书卸载
缓存功能：支持内容缓存
压缩功能：支持gzip压缩

二、nginx负载均衡基础配置

2.1 upstream模块详解

upstream基本语法

# =============================================
# upstream模块基础配置
# =============================================

# 定义后端服务器组
upstream backend_servers {
    # 服务器地址和端口
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080;
    
    # 负载均衡方法
    # 默认为轮询（round-robin）
    # least_conn;     # 最少连接
    # ip_hash;        # ip哈希
    # hash $request_uri; # 一致性哈希
}

server {
    listen 80;
    server_name lb.example.com;
    
    location / {
        # 代理到后端服务器组
        proxy_pass http://backend_servers;
        
        # 设置代理头信息
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
    }
}

upstream参数详解

# =============================================
# upstream服务器参数详解
# =============================================

upstream backend_servers {
    # 基本服务器配置
    server 192.168.1.10:8080 weight=5 max_fails=3 fail_timeout=30s backup;
    server 192.168.1.11:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 weight=2 max_fails=3 fail_timeout=30s down;
    
    # 服务器参数说明：
    # weight: 权重，数值越大分配到的请求越多
    # max_fails: 最大失败次数，超过则标记为不可用
    # fail_timeout: 失败超时时间，单位秒
    # backup: 备份服务器，主服务器都不可用时启用
    # down: 标记服务器永久不可用
    # max_conns: 最大连接数限制
    # resolve: 动态解析域名
    # service: 服务发现配置
    # slow_start: 慢启动时间
    
    # 负载均衡方法
    least_conn;
    
    # 连接保持配置
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
    
    # 会话保持配置
    sticky cookie srv_id expires=1h domain=.example.com path=/;
    
    # 健康检查配置
    health_check interval=10s fails=3 passes=2 uri=/health port=8080;
}

2.2 基础负载均衡配置

简单轮询负载均衡

# =============================================
# 简单轮询负载均衡配置
# =============================================

# 定义后端服务器组（轮询方式）
upstream backend_round_robin {
    # 轮询方式（默认）
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080;
    
    # 连接保持配置
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name round-robin.example.com;
    
    access_log /var/log/nginx/round-robin.example.com.access.log main;
    error_log /var/log/nginx/round-robin.example.com.error.log warn;
    
    location / {
        # 代理到后端服务器组
        proxy_pass http://backend_round_robin;
        
        # 设置代理头信息
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        # 连接设置
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        # 超时设置
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 缓冲区设置
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
        proxy_busy_buffers_size 8k;
        
        # 添加负载均衡信息到响应头
        add_header x-upstream-addr $upstream_addr;
        add_header x-upstream-response-time $upstream_response_time;
    }
    
    # =============================================
    # 健康检查端点
    # =============================================
    
    location /health {
        access_log off;
        return 200 "healthy\n";
        add_header content-type text/plain;
    }
}

带权重轮询负载均衡

# =============================================
# 带权重轮询负载均衡配置
# =============================================

# 定义后端服务器组（加权轮询）
upstream backend_weighted {
    # 权重分配，数值越大分配到的请求越多
    server 192.168.1.10:8080 weight=5;    # 50%的请求
    server 192.168.1.11:8080 weight=3;    # 30%的请求
    server 192.168.1.12:8080 weight=2;    # 20%的请求
    
    # 健康检查设置
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name weighted.example.com;
    
    access_log /var/log/nginx/weighted.example.com.access.log main;
    error_log /var/log/nginx/weighted.example.com.error.log warn;
    
    location / {
        proxy_pass http://backend_weighted;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
        proxy_busy_buffers_size 8k;
        
        # 添加权重信息到响应头
        add_header x-upstream-addr $upstream_addr;
        add_header x-upstream-weight "5:3:2";
        add_header x-upstream-response-time $upstream_response_time;
    }
    
    # =============================================
    # 负载均衡统计
    # =============================================
    
    location /lb_stats {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 显示负载均衡统计信息
        add_header content-type "application/json";
        return 200 '{
            "algorithm": "weighted_round_robin",
            "servers": [
                {"addr": "192.168.1.10:8080", "weight": 5, "status": "up"},
                {"addr": "192.168.1.11:8080", "weight": 3, "status": "up"},
                {"addr": "192.168.1.12:8080", "weight": 2, "status": "up"}
            ]
        }';
    }
}

三、负载均衡策略详解

3.1 轮询策略（round robin）

基础轮询配置

# =============================================
# 轮询策略配置
# =============================================

# 定义后端服务器组（轮询）
upstream backend_round_robin {
    # 轮询方式（默认）
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080;
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name rr.example.com;
    
    location / {
        proxy_pass http://backend_round_robin;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加轮询信息
        add_header x-lb-algorithm "round_robin";
        add_header x-upstream-addr $upstream_addr;
    }
}

轮询策略特点

工作原理：

按照顺序将请求依次分配到后端服务器
第一个请求分配到服务器1，第二个到服务器2，以此类推
循环往复，实现均匀分配

适用场景：

后端服务器性能相近
请求处理时间相似
不需要会话保持

优缺点：

✅ 配置简单，易于理解
✅ 请求分配均匀
❌ 不考虑服务器性能差异
❌ 不考虑当前连接数

3.2 加权轮询策略（weighted round robin）

加权轮询配置

# =============================================
# 加权轮询策略配置
# =============================================

# 定义后端服务器组（加权轮询）
upstream backend_weighted {
    # 权重分配
    server 192.168.1.10:8080 weight=5;    # 高性能服务器
    server 192.168.1.11:8080 weight=3;    # 中等性能服务器
    server 192.168.1.12:8080 weight=2;    # 低性能服务器
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name wrr.example.com;
    
    location / {
        proxy_pass http://backend_weighted;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加权重信息
        add_header x-lb-algorithm "weighted_round_robin";
        add_header x-upstream-addr $upstream_addr;
        add_header x-upstream-weight "5:3:2";
    }
}

加权轮询策略特点

工作原理：

根据服务器权重分配请求
权重越高，分配到的请求越多
权重比例为5:3:2，则请求分配比例约为50%:30%:20%

适用场景：

后端服务器性能差异较大
服务器配置不同
需要根据性能分配负载

优缺点：

✅ 考虑服务器性能差异
✅ 灵活配置负载分配
✅ 优化资源利用率
❌ 需要手动调整权重
❌ 不考虑实时负载情况

3.3 ip哈希策略（ip hash）

ip哈希配置

# =============================================
# ip哈希策略配置
# =============================================

# 定义后端服务器组（ip哈希）
upstream backend_ip_hash {
    # ip哈希方式，确保同一客户端请求始终转发到同一服务器
    ip_hash;
    
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080;
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name iphash.example.com;
    
    location / {
        proxy_pass http://backend_ip_hash;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加哈希信息
        add_header x-lb-algorithm "ip_hash";
        add_header x-upstream-addr $upstream_addr;
        add_header x-client-ip $remote_addr;
    }
}

ip哈希策略特点

工作原理：

基于客户端ip地址计算哈希值
同一ip的请求始终分配到同一服务器
确保会话一致性

适用场景：

需要会话保持
使用本地会话存储
无分布式会话

优缺点：

✅ 会话保持，用户体验好
✅ 配置简单
❌ 负载分配不均匀
❌ 服务器故障时影响大
❌ 不支持动态添加服务器

3.4 最少连接策略（least connections）

最少连接配置

# =============================================
# 最少连接策略配置
# =============================================

# 定义后端服务器组（最少连接）
upstream backend_least_conn {
    # 最少连接方式，将请求转发到连接数最少的服务器
    least_conn;
    
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080;
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name leastconn.example.com;
    
    location / {
        proxy_pass http://backend_least_conn;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加连接数信息
        add_header x-lb-algorithm "least_conn";
        add_header x-upstream-addr $upstream_addr;
        add_header x-upstream-connections $upstream_connections;
    }
}

最少连接策略特点

工作原理：

实时监控各服务器的连接数
将新请求分配到连接数最少的服务器
动态调整负载分配

适用场景：

请求处理时间差异较大
需要动态负载均衡
长连接应用

优缺点：

✅ 动态负载均衡
✅ 响应时间更优
✅ 资源利用率高
❌ 需要实时监控连接数
❌ 配置相对复杂

3.5 一致性哈希策略（consistent hash）

一致性哈希配置

# =============================================
# 一致性哈希策略配置
# =============================================

# 定义后端服务器组（一致性哈希）
upstream backend_consistent_hash {
    # 一致性哈希方式
    hash $request_uri consistent;
    
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080;
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name consistent.example.com;
    
    location / {
        proxy_pass http://backend_consistent_hash;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加哈希信息
        add_header x-lb-algorithm "consistent_hash";
        add_header x-upstream-addr $upstream_addr;
        add_header x-hash-key $request_uri;
    }
}

一致性哈希策略特点

工作原理：

基于请求特征（如uri）计算哈希值
相同特征的请求分配到同一服务器
支持动态添加/删除服务器

适用场景：

缓存系统
分布式存储
需要数据一致性

优缺点：

✅ 支持动态扩容
✅ 数据一致性好
✅ 负载分配相对均匀
❌ 配置复杂
❌ 需要选择合适的哈希键

3.6 策略对比总结

策略	适用场景	优点	缺点
轮询	服务器性能相近	配置简单，分配均匀	不考虑性能差异
加权轮询	服务器性能差异大	考虑性能差异	需要手动调整权重
ip哈希	需要会话保持	会话保持	负载不均匀
最少连接	请求处理时间差异大	动态负载均衡	配置复杂
一致性哈希	缓存系统	支持动态扩容	配置复杂

四、高级负载均衡配置

4.1 健康检查配置

被动健康检查

# =============================================
# 被动健康检查配置
# =============================================

upstream backend_health_check {
    # 后端服务器配置
    server 192.168.1.10:8080 weight=5 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 weight=2 max_fails=3 fail_timeout=30s backup;
    
    # 负载均衡方法
    least_conn;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name health.example.com;
    
    location / {
        proxy_pass http://backend_health_check;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加健康检查信息
        add_header x-upstream-status $upstream_status;
        add_header x-upstream-response-time $upstream_response_time;
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 健康检查端点
    # =============================================
    
    location /health {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 返回健康状态
        add_header content-type "application/json";
        return 200 '{
            "status": "healthy",
            "upstream": "backend_health_check",
            "servers": [
                {"addr": "192.168.1.10:8080", "status": "up"},
                {"addr": "192.168.1.11:8080", "status": "up"},
                {"addr": "192.168.1.12:8080", "status": "backup"}
            ]
        }';
    }
}

主动健康检查（需要nginx_plus或第三方模块）

# =============================================
# 主动健康检查配置（需要nginx_plus）
# =============================================

upstream backend_active_health {
    zone backend_active_health 64k;
    
    server 192.168.1.10:8080 slow_start=30s;
    server 192.168.1.11:8080 slow_start=30s;
    server 192.168.1.12:8080 slow_start=30s backup;
    
    # 主动健康检查
    health_check interval=10s fails=3 passes=2 uri=/health port=8080;
    
    # 负载均衡
    least_conn;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name active-health.example.com;
    
    location / {
        proxy_pass http://backend_active_health;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加健康状态信息
        add_header x-upstream-status $upstream_status;
        add_header x-upstream-response-time $upstream_response_time;
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 健康状态监控
    # =============================================
    
    location /upstream_status {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 显示上游服务器状态
        upstream_status;
        
        add_header content-type "text/plain";
    }
}

4.2 会话保持配置

cookie会话保持

# =============================================
# cookie会话保持配置
# =============================================

upstream backend_sticky {
    # cookie会话保持
    sticky cookie srv_id expires=1h domain=.example.com path=/ httponly secure;
    
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080;
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name sticky.example.com;
    
    location / {
        proxy_pass http://backend_sticky;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加会话保持信息
        add_header x-lb-session-sticky "cookie";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 会话管理
    # =============================================
    
    location /session {
        # 显示会话信息
        add_header content-type "application/json";
        return 200 '{
            "session_id": "$cookie_srv_id",
            "upstream_addr": "$upstream_addr",
            "session_sticky": "enabled"
        }';
    }
}

路由会话保持

# =============================================
# 路由会话保持配置
# =============================================

upstream backend_route {
    # 路由会话保持
    sticky route $route_cookie $route_uri;
    
    server 192.168.1.10:8080 route=a;
    server 192.168.1.11:8080 route=b;
    server 192.168.1.12:8080 route=c;
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name route.example.com;
    
    location / {
        proxy_pass http://backend_route;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加路由信息
        add_header x-lb-session-sticky "route";
        add_header x-upstream-addr $upstream_addr;
        add_header x-route $route_cookie;
    }
}

4.3 动态负载均衡配置

基于dns的动态负载均衡

# =============================================
# 基于dns的动态负载均衡配置
# =============================================

upstream backend_dynamic {
    # 启用dns解析
    resolver 8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout 5s;
    
    # 动态服务器配置
    server web1.example.com:8080 resolve;
    server web2.example.com:8080 resolve;
    server web3.example.com:8080 resolve;
    
    # 健康检查
    server web1.example.com:8080 max_fails=3 fail_timeout=30s;
    server web2.example.com:8080 max_fails=3 fail_timeout=30s;
    server web3.example.com:8080 max_fails=3 fail_timeout=30s;
    
    # 负载均衡方法
    least_conn;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name dynamic.example.com;
    
    location / {
        proxy_pass http://backend_dynamic;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加动态信息
        add_header x-lb-dynamic "dns_based";
        add_header x-upstream-addr $upstream_addr;
    }
}

基于服务发现的动态负载均衡

# =============================================
# 基于服务发现的动态负载均衡配置
# =============================================

upstream backend_service_discovery {
    # 服务发现配置
    zone backend_service_discovery 64k;
    
    # 动态服务器配置
    server backend-service-1.example.com:8080 service=backend resolve;
    server backend-service-2.example.com:8080 service=backend resolve;
    server backend-service-3.example.com:8080 service=backend resolve;
    
    # 健康检查
    health_check interval=10s fails=3 passes=2 uri=/health port=8080;
    
    # 负载均衡方法
    least_conn;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name service-discovery.example.com;
    
    location / {
        proxy_pass http://backend_service_discovery;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加服务发现信息
        add_header x-lb-service-discovery "enabled";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 服务发现状态
    # =============================================
    
    location /service_status {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 显示服务发现状态
        add_header content-type "application/json";
        return 200 '{
            "service_discovery": "enabled",
            "upstream": "backend_service_discovery",
            "services": [
                {"name": "backend-service-1", "status": "up"},
                {"name": "backend-service-2", "status": "up"},
                {"name": "backend-service-3", "status": "up"}
            ]
        }';
    }
}

4.4 灰度发布配置

基于权重的灰度发布

# =============================================
# 基于权重的灰度发布配置
# =============================================

upstream backend_canary {
    # 灰度发布配置
    # 旧版本：80%流量
    # 新版本：20%流量
    server 192.168.1.10:8080 weight=8;    # 旧版本
    server 192.168.1.20:8080 weight=2;    # 新版本
    
    # 健康检查
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.20:8080 max_fails=3 fail_timeout=30s;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name canary.example.com;
    
    location / {
        proxy_pass http://backend_canary;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加灰度发布信息
        add_header x-canary-deployment "enabled";
        add_header x-upstream-addr $upstream_addr;
        add_header x-version-weight "8:2";
    }
    
    # =============================================
    # 版本信息
    # =============================================
    
    location /version {
        # 显示版本信息
        add_header content-type "application/json";
        return 200 '{
            "canary_deployment": "enabled",
            "old_version": {"weight": 8, "addr": "192.168.1.10:8080"},
            "new_version": {"weight": 2, "addr": "192.168.1.20:8080"}
        }';
    }
}

基于用户特征的灰度发布

# =============================================
# 基于用户特征的灰度发布配置
# =============================================

# 定义用户特征映射
map $cookie_user_id $user_group {
    default "old";
    "~^user[0-9]{1,3}$" "new";  # 用户id为user001-user999的用户分配到新版本
}

# 定义后端服务器组
upstream backend_user_canary {
    server 192.168.1.10:8080;    # 旧版本
    server 192.168.1.20:8080;    # 新版本
}

server {
    listen 80;
    server_name user-canary.example.com;
    
    location / {
        # 根据用户组选择后端
        if ($user_group = "new") {
            proxy_pass http://192.168.1.20:8080;
        }
        
        if ($user_group = "old") {
            proxy_pass http://192.168.1.10:8080;
        }
        
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 添加用户灰度信息
        add_header x-canary-user-based "enabled";
        add_header x-user-group $user_group;
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 用户组信息
    # =============================================
    
    location /user_group {
        # 显示用户组信息
        add_header content-type "application/json";
        return 200 '{
            "user_canary": "enabled",
            "user_id": "$cookie_user_id",
            "user_group": "$user_group",
            "upstream_addr": "$upstream_addr"
        }';
    }
}

五、负载均衡监控与故障处理

5.1 负载均衡监控配置

状态监控配置

# =============================================
# 负载均衡监控配置
# =============================================

http {
    # =============================================
    # 监控日志格式
    # =============================================
    
    # 负载均衡监控日志格式
    log_format lb_monitor '$remote_addr - $remote_user [$time_local] "$request" '
                        '$status $body_bytes_sent "$http_referer" '
                        '"$http_user_agent" "$http_x_forwarded_for" '
                        'upstream_addr="$upstream_addr" '
                        'upstream_status="$upstream_status" '
                        'upstream_response_time="$upstream_response_time" '
                        'upstream_connect_time="$upstream_connect_time" '
                        'upstream_header_time="$upstream_header_time"';
    
    # =============================================
    # 监控服务器配置
    # =============================================
    
    server {
        listen 80;
        server_name monitor.example.com;
        
        # 负载均衡状态页面
        location /lb_status {
            # 限制访问
            allow 127.0.0.1;
            allow 192.168.1.0/24;
            deny all;
            
            # 显示负载均衡状态
            stub_status on;
            
            add_header content-type "text/plain";
        }
        
        # 上游服务器状态
        location /upstream_status {
            # 限制访问
            allow 127.0.0.1;
            allow 192.168.1.0/24;
            deny all;
            
            # 显示上游服务器状态
            upstream_status;
            
            add_header content-type "text/plain";
        }
        
        # 实时监控数据
        location /real_time_stats {
            # 限制访问
            allow 127.0.0.1;
            allow 192.168.1.0/24;
            deny all;
            
            # 实时统计信息
            add_header content-type "application/json";
            return 200 '{
                "timestamp": "$time_iso8601",
                "connections": {
                    "active": $connections_active,
                    "reading": $connections_reading,
                    "writing": $connections_writing,
                    "waiting": $connections_waiting
                },
                "requests": {
                    "total": $request_counter,
                    "current": $connections_active
                }
            }';
        }
        
        # 历史统计数据
        location /historical_stats {
            # 限制访问
            allow 127.0.0.1;
            allow 192.168.1.0/24;
            deny all;
            
            # 显示历史统计信息
            add_header content-type "application/json";
            return 200 '{
                "historical_data": "available_in_log_files",
                "log_file": "/var/log/nginx/lb_monitor.log",
                "retention_days": 30
            }';
        }
    }
}

监控脚本配置

# =============================================
# 负载均衡监控脚本
# 创建 /usr/local/nginx/scripts/lb_monitor.sh
# =============================================

#!/bin/bash

# nginx负载均衡监控脚本
# 用法：./lb_monitor.sh

# 配置参数
nginx_status_url="http://localhost/lb_status"
upstream_status_url="http://localhost/upstream_status"
log_file="/var/log/nginx/lb_monitor.log"
alert_email="admin@example.com"
alert_threshold=1000

# 获取nginx状态
get_nginx_status() {
    curl -s $nginx_status_url
}

# 获取上游服务器状态
get_upstream_status() {
    curl -s $upstream_status_url
}

# 解析nginx状态
parse_nginx_status() {
    local status=$(get_nginx_status)
    local active_connections=$(echo "$status" | grep "active connections" | awk '{print $3}')
    local accepts=$(echo "$status" | awk 'nr==3 {print $1}')
    local handled=$(echo "$status" | awk 'nr==3 {print $2}')
    local requests=$(echo "$status" | awk 'nr==3 {print $3}')
    local reading=$(echo "$status" | awk 'nr==4 {print $2}')
    local writing=$(echo "$status" | awk 'nr==4 {print $4}')
    local waiting=$(echo "$status" | awk 'nr==4 {print $6}')
    
    echo "active connections: $active_connections"
    echo "accepts: $accepts"
    echo "handled: $handled"
    echo "requests: $requests"
    echo "reading: $reading"
    echo "writing: $writing"
    echo "waiting: $waiting"
    
    # 检查是否超过阈值
    if [ "$active_connections" -gt "$alert_threshold" ]; then
        echo "warning: active connections exceed threshold: $active_connections > $alert_threshold"
        send_alert "high active connections detected: $active_connections"
    fi
}

# 解析上游服务器状态
parse_upstream_status() {
    local status=$(get_upstream_status)
    echo "upstream server status:"
    echo "$status"
    
    # 检查是否有服务器宕机
    if echo "$status" | grep -q "down"; then
        echo "warning: some upstream servers are down"
        send_alert "upstream server down detected"
    fi
}

# 发送告警
send_alert() {
    local message=$1
    echo "[$(date)] alert: $message" >> $log_file
    echo "$message" | mail -s "nginx load balancer alert" $alert_email
}

# 记录监控数据
log_monitor_data() {
    local timestamp=$(date "+%y-%m-%d %h:%m:%s")
    local status=$(get_nginx_status)
    local active_connections=$(echo "$status" | grep "active connections" | awk '{print $3}')
    local upstream_status=$(get_upstream_status)
    
    echo "$timestamp, $active_connections, $upstream_status" >> $log_file
}

# 主函数
main() {
    echo "=== nginx load balancer monitor ==="
    echo "timestamp: $(date)"
    echo ""
    
    echo "nginx status:"
    parse_nginx_status
    echo ""
    
    echo "upstream status:"
    parse_upstream_status
    echo ""
    
    echo "logging monitor data..."
    log_monitor_data
    
    echo "monitoring completed."
}

# 执行主函数
main

5.2 故障处理配置

故障转移配置

# =============================================
# 故障转移配置
# =============================================

upstream backend_failover {
    # 主服务器
    server 192.168.1.10:8080 weight=5 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 weight=3 max_fails=3 fail_timeout=30s;
    
    # 备份服务器
    server 192.168.1.20:8080 backup;
    server 192.168.1.21:8080 backup;
    
    # 负载均衡方法
    least_conn;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name failover.example.com;
    
    location / {
        proxy_pass http://backend_failover;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 故障转移配置
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
        proxy_next_upstream_tries 3;
        proxy_next_upstream_timeout 10s;
        
        # 添加故障转移信息
        add_header x-failover "enabled";
        add_header x-upstream-addr $upstream_addr;
        add_header x-upstream-status $upstream_status;
    }
    
    # =============================================
    # 故障状态页面
    # =============================================
    
    location /failover_status {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 显示故障转移状态
        add_header content-type "application/json";
        return 200 '{
            "failover": "enabled",
            "primary_servers": [
                {"addr": "192.168.1.10:8080", "status": "up"},
                {"addr": "192.168.1.11:8080", "status": "up"}
            ],
            "backup_servers": [
                {"addr": "192.168.1.20:8080", "status": "standby"},
                {"addr": "192.168.1.21:8080", "status": "standby"}
            ]
        }';
    }
}

熔断器配置

# =============================================
# 熔断器配置
# =============================================

# 定义熔断器状态变量
map $upstream_addr $circuit_breaker_status {
    default "closed";
    192.168.1.10:8080 "closed";
    192.168.1.11:8080 "closed";
    192.168.1.12:8080 "closed";
}

upstream backend_circuit_breaker {
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 max_fails=3 fail_timeout=30s;
    
    # 负载均衡方法
    least_conn;
    
    # 连接保持
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name circuit-breaker.example.com;
    
    location / {
        # 熔断器检查
        if ($circuit_breaker_status = "open") {
            return 503 "service unavailable - circuit breaker open";
        }
        
        proxy_pass http://backend_circuit_breaker;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 5s;
        proxy_send_timeout 5s;
        proxy_read_timeout 5s;
        
        # 熔断器配置
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
        proxy_next_upstream_tries 2;
        proxy_next_upstream_timeout 5s;
        
        # 添加熔断器信息
        add_header x-circuit-breaker $circuit_breaker_status;
        add_header x-upstream-addr $upstream_addr;
        add_header x-upstream-status $upstream_status;
    }
    
    # =============================================
    # 熔断器状态管理
    # =============================================
    
    location /circuit_breaker {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 熔断器控制
        if ($args ~* "action=open") {
            return 200 'circuit breaker opened manually';
        }
        
        if ($args ~* "action=close") {
            return 200 'circuit breaker closed manually';
        }
        
        # 显示熔断器状态
        add_header content-type "application/json";
        return 200 '{
            "circuit_breaker": "enabled",
            "status": "$circuit_breaker_status",
            "upstream_addr": "$upstream_addr",
            "upstream_status": "$upstream_status"
        }';
    }
}

六、实战案例

6.1 电商网站负载均衡配置

电商网站负载均衡架构

# =============================================
# 电商网站负载均衡配置
# =============================================

# 用户服务负载均衡
upstream user_service {
    least_conn;
    server 192.168.1.10:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 weight=2 max_fails=3 fail_timeout=30s backup;
    
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

# 商品服务负载均衡
upstream product_service {
    ip_hash;
    server 192.168.1.20:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.21:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.22:8080 max_fails=3 fail_timeout=30s backup;
    
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

# 订单服务负载均衡
upstream order_service {
    least_conn;
    server 192.168.1.30:8080 weight=4 max_fails=3 fail_timeout=30s;
    server 192.168.1.31:8080 weight=4 max_fails=3 fail_timeout=30s;
    server 192.168.1.32:8080 weight=2 max_fails=3 fail_timeout=30s backup;
    
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

# 支付服务负载均衡
upstream payment_service {
    least_conn;
    server 192.168.1.40:8080 weight=5 max_fails=2 fail_timeout=15s;
    server 192.168.1.41:8080 weight=5 max_fails=2 fail_timeout=15s;
    server 192.168.1.42:8080 backup;
    
    keepalive 16;
    keepalive_timeout 30s;
    keepalive_requests 500;
}

server {
    listen 80;
    server_name ecommerce.example.com;
    
    access_log /var/log/nginx/ecommerce.example.com.access.log main;
    error_log /var/log/nginx/ecommerce.example.com.error.log warn;
    
    # =============================================
    # 静态资源
    # =============================================
    
    location ~* \.(jpg|jpeg|png|gif|ico|css|js|woff|woff2|ttf|eot|svg)$ {
        root /usr/local/nginx/html/ecommerce;
        expires 7d;
        add_header cache-control "public, no-transform";
        access_log off;
    }
    
    # =============================================
    # 用户服务
    # =============================================
    
    location /api/user/ {
        proxy_pass http://user_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        # 用户服务会话保持
        proxy_cookie_path / /;
        proxy_cookie_domain off;
        
        # 添加服务标识
        add_header x-service "user_service";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 商品服务
    # =============================================
    
    location /api/product/ {
        proxy_pass http://product_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        # 商品服务缓存
        proxy_cache product_cache;
        proxy_cache_valid 200 302 10m;
        proxy_cache_valid 404 1m;
        proxy_cache_key $scheme$request_method$host$request_uri;
        
        # 添加服务标识
        add_header x-service "product_service";
        add_header x-upstream-addr $upstream_addr;
        add_header x-cache-status $upstream_cache_status;
    }
    
    # =============================================
    # 订单服务
    # =============================================
    
    location /api/order/ {
        proxy_pass http://order_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 订单服务重试机制
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
        proxy_next_upstream_tries 3;
        
        # 添加服务标识
        add_header x-service "order_service";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 支付服务
    # =============================================
    
    location /api/payment/ {
        proxy_pass http://payment_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        # 支付服务严格超时
        proxy_next_upstream error timeout;
        proxy_next_upstream_tries 2;
        
        # 添加服务标识
        add_header x-service "payment_service";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 健康检查
    # =============================================
    
    location /health {
        access_log off;
        return 200 "healthy\n";
        add_header content-type text/plain;
    }
    
    # =============================================
    # 服务状态
    # =============================================
    
    location /service_status {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 显示服务状态
        add_header content-type "application/json";
        return 200 '{
            "services": {
                "user_service": {"status": "active", "algorithm": "least_conn"},
                "product_service": {"status": "active", "algorithm": "ip_hash"},
                "order_service": {"status": "active", "algorithm": "least_conn"},
                "payment_service": {"status": "active", "algorithm": "least_conn"}
            }
        }';
    }
}

6.2 微服务架构负载均衡配置

微服务负载均衡架构

# =============================================
# 微服务架构负载均衡配置
# =============================================

# api网关负载均衡
upstream api_gateway {
    least_conn;
    server 192.168.1.10:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.12:8080 weight=2 max_fails=3 fail_timeout=30s backup;
    
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

# 认证服务负载均衡
upstream auth_service {
    least_conn;
    server 192.168.1.20:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.21:8080 max_fails=3 fail_timeout=30s;
    
    keepalive 16;
    keepalive_timeout 30s;
    keepalive_requests 500;
}

# 用户服务负载均衡
upstream user_service {
    ip_hash;
    server 192.168.1.30:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.31:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.32:8080 max_fails=3 fail_timeout=30s backup;
    
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

# 业务服务负载均衡
upstream business_service {
    least_conn;
    server 192.168.1.40:8080 weight=2 max_fails=3 fail_timeout=30s;
    server 192.168.1.41:8080 weight=2 max_fails=3 fail_timeout=30s;
    server 192.168.1.42:8080 weight=1 max_fails=3 fail_timeout=30s;
    server 192.168.1.43:8080 weight=1 max_fails=3 fail_timeout=30s backup;
    
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

# 消息服务负载均衡
upstream message_service {
    least_conn;
    server 192.168.1.50:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.51:8080 max_fails=3 fail_timeout=30s;
    
    keepalive 16;
    keepalive_timeout 30s;
    keepalive_requests 500;
}

# 文件服务负载均衡
upstream file_service {
    least_conn;
    server 192.168.1.60:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.61:8080 weight=3 max_fails=3 fail_timeout=30s;
    server 192.168.1.62:8080 weight=2 max_fails=3 fail_timeout=30s backup;
    
    keepalive 32;
    keepalive_timeout 30s;
    keepalive_requests 1000;
}

server {
    listen 80;
    server_name microservice.example.com;
    
    access_log /var/log/nginx/microservice.example.com.access.log main;
    error_log /var/log/nginx/microservice.example.com.error.log warn;
    
    # =============================================
    # api网关
    # =============================================
    
    location / {
        proxy_pass http://api_gateway;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        # api网关重试机制
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
        proxy_next_upstream_tries 3;
        
        # 添加网关标识
        add_header x-gateway "nginx";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 内部服务路由
    # =============================================
    
    # 认证服务
    location /internal/auth/ {
        proxy_pass http://auth_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        # 认证服务缓存
        proxy_cache auth_cache;
        proxy_cache_valid 200 302 5m;
        proxy_cache_valid 404 1m;
        proxy_cache_key $scheme$request_method$host$request_uri;
        
        add_header x-service "auth_service";
        add_header x-upstream-addr $upstream_addr;
        add_header x-cache-status $upstream_cache_status;
    }
    
    # 用户服务
    location /internal/user/ {
        proxy_pass http://user_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        add_header x-service "user_service";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # 业务服务
    location /internal/business/ {
        proxy_pass http://business_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        # 业务服务重试机制
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
        proxy_next_upstream_tries 3;
        
        add_header x-service "business_service";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # 消息服务
    location /internal/message/ {
        proxy_pass http://message_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        add_header x-service "message_service";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # 文件服务
    location /internal/file/ {
        proxy_pass http://file_service;
        proxy_set_header host $host;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header x-forwarded-proto $scheme;
        
        proxy_http_version 1.1;
        proxy_set_header connection "";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # 文件服务大文件支持
        client_max_body_size 100m;
        proxy_max_temp_file_size 1024m;
        
        add_header x-service "file_service";
        add_header x-upstream-addr $upstream_addr;
    }
    
    # =============================================
    # 服务发现和健康检查
    # =============================================
    
    location /service_discovery {
        # 限制访问
        allow 127.0.0.1;
        allow 192.168.1.0/24;
        deny all;
        
        # 显示服务发现状态
        add_header content-type "application/json";
        return 200 '{
            "microservices": {
                "api_gateway": {"status": "active", "servers": 3},
                "auth_service": {"status": "active", "servers": 2},
                "user_service": {"status": "active", "servers": 3},
                "business_service": {"status": "active", "servers": 4},
                "message_service": {"status": "active", "servers": 2},
                "file_service": {"status": "active", "servers": 3}
            }
        }';
    }
    
    # =============================================
    # 健康检查
    # =============================================
    
    location /health {
        access_log off;
        return 200 "healthy\n";
        add_header content-type text/plain;
    }
}

性能优化建议：

合理配置连接保持参数
启用缓存提高响应速度
根据服务器性能配置权重
实现动态扩容和缩容
定期监控和优化负载均衡效果

高可用性建议：

配置备份服务器
实现故障自动转移
建立熔断机制防止雪崩
实现灰度发布降低风险
定期演练故障恢复流程

nginx负载均衡是构建高可用、高性能系统的关键技术。通过本文的学习，你应该能够根据实际业务需求，设计并实现合适的负载均衡方案，为系统的稳定运行提供有力保障。

以上就是nginx中多种负载均衡策略配置的实战指南的详细内容，更多关于nginx负载均衡的资料请关注代码网其它相关文章！

Nginx中多种负载均衡策略配置的实战指南

2025年10月24日 • Linux •我要评论

前言

一、负载均衡基础概念

1.1 什么是负载均衡

1.2 负载均衡类型

1.3 nginx负载均衡优势

二、nginx负载均衡基础配置

2.1 upstream模块详解

2.2 基础负载均衡配置

三、负载均衡策略详解

3.1 轮询策略（round robin）

3.2 加权轮询策略（weighted round robin）

3.3 ip哈希策略（ip hash）

3.4 最少连接策略（least connections）

3.5 一致性哈希策略（consistent hash）

3.6 策略对比总结

四、高级负载均衡配置

4.1 健康检查配置

4.2 会话保持配置

4.3 动态负载均衡配置

4.4 灰度发布配置

五、负载均衡监控与故障处理

5.1 负载均衡监控配置

5.2 故障处理配置

六、实战案例

6.1 电商网站负载均衡配置

6.2 微服务架构负载均衡配置

相关文章:

Linux的GPIO驱动程序使用详解

发表评论


验证码：