Nginx 如何进行监控和运维？有哪些监控工具？

Nginx 的监控和运维对于保证服务稳定性和性能至关重要。合理的监控可以及时发现和解决问题。

内置状态监控：

nginx
# 启用 stub_status 模块
server {
    listen 80;
    server_name localhost;
    
    location /nginx_status {
        stub_status on;
        access_log off;
        allow 127.0.0.1;
        deny all;
    }
}

状态信息说明：

Active connections：当前活动连接数
accepts：已接受的连接总数
handled：已处理的连接总数
requests：已处理的请求总数
Reading：正在读取请求头的连接数
Writing：正在发送响应的连接数
Waiting：空闲连接数

自定义监控端点：

nginx
server {
    listen 80;
    server_name localhost;
    
    # 健康检查
    location /health {
        access_log off;
        return 200 "OK\n";
        add_header Content-Type text/plain;
    }
    
    # 就绪检查
    location /ready {
        access_log off;
        # 检查后端连接
        proxy_pass http://backend/health;
        proxy_intercept_errors off;
    }
    
    # 版本信息
    location /version {
        access_log off;
        return 200 "Nginx/1.21.0\n";
        add_header Content-Type text/plain;
    }
}

日志监控：

nginx
# 自定义日志格式
log_format monitoring '$remote_addr - $remote_user [$time_local] '
                   '"$request" $status $body_bytes_sent '
                   '"$http_referer" "$http_user_agent" '
                   'rt=$request_time uct="$upstream_connect_time" '
                   'uht="$upstream_header_time" urt="$upstream_response_time" '
                   'cache=$upstream_cache_status';

server {
    listen 80;
    server_name example.com;
    
    access_log /var/log/nginx/monitoring.log monitoring;
    
    location / {
        proxy_pass http://backend;
    }
}

Prometheus 监控：

nginx
# 安装 nginx-prometheus-exporter
# https://github.com/nginxinc/nginx-prometheus-exporter

# 配置 Nginx
server {
    listen 80;
    server_name localhost;
    
    location /metrics {
        proxy_pass http://localhost:9113/metrics;
        access_log off;
        allow 127.0.0.1;
        deny all;
    }
}

Grafana + Prometheus 监控：

yaml
# prometheus.yml
global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'nginx'
    static_configs:
      - targets: ['localhost:9113']

ELK Stack 监控：

nginx
# JSON 格式日志
log_format json_combined escape=json '{'
    '"time_local":"$time_local",'
    '"remote_addr":"$remote_addr",'
    '"remote_user":"$remote_user",'
    '"request":"$request",'
    '"status":"$status",'
    '"body_bytes_sent":"$body_bytes_sent",'
    '"request_time":"$request_time",'
    '"http_referrer":"$http_referer",'
    '"http_user_agent":"$http_user_agent"'
'}';

server {
    listen 80;
    server_name example.com;
    
    access_log /var/log/nginx/access.log json_combined;
    
    location / {
        proxy_pass http://backend;
    }
}

Zabbix 监控：

bash
# 安装 Zabbix Agent
# 配置监控项
# nginx_status[accepts]
# nginx_status[handled]
# nginx_status[requests]
# nginx_status[reading]
# nginx_status[writing]
# nginx_status[waiting]

性能监控指标：

nginx
# 启用详细日志
log_format performance '$remote_addr - $remote_user [$time_local] '
                     '"$request" $status $body_bytes_sent '
                     'rt=$request_time '
                     'uct=$upstream_connect_time '
                     'uht=$upstream_header_time '
                     'urt=$upstream_response_time '
                     'cache=$upstream_cache_status';

server {
    listen 80;
    server_name example.com;
    
    access_log /var/log/nginx/performance.log performance;
    
    location / {
        proxy_pass http://backend;
    }
}

告警配置：

nginx
# 基于日志的告警
map $status $alert_level {
    ~^[5]  critical;
    ~^[4]  warning;
    default ok;
}

server {
    listen 80;
    server_name example.com;
    
    access_log /var/log/nginx/access.log performance;
    
    location / {
        proxy_pass http://backend;
        
        # 添加告警头
        add_header X-Alert-Level $alert_level;
    }
}

自动化运维脚本：

bash
#!/bin/bash
# nginx_monitor.sh

# 检查 Nginx 状态
check_nginx_status() {
    if ! curl -f http://localhost/nginx_status > /dev/null 2>&1; then
        echo "Nginx status page is not accessible"
        return 1
    fi
    return 0
}

# 检查进程
check_nginx_process() {
    if ! pgrep -x nginx > /dev/null; then
        echo "Nginx process is not running"
        return 1
    fi
    return 0
}

# 检查端口
check_nginx_port() {
    if ! netstat -tlnp | grep :80 > /dev/null; then
        echo "Nginx is not listening on port 80"
        return 1
    fi
    return 0
}

# 主函数
main() {
    check_nginx_status
    check_nginx_process
    check_nginx_port
    
    echo "All checks passed"
}

main

运维命令：

bash
# 重载配置（不中断服务）
nginx -s reload

# 优雅停止
nginx -s quit

# 快速停止
nginx -s stop

# 重新打开日志文件
nginx -s reopen

# 测试配置
nginx -t

# 查看版本
nginx -v

# 查看编译参数
nginx -V

日志轮转：

bash
# /etc/logrotate.d/nginx
/var/log/nginx/*.log {
    daily
    missingok
    rotate 14
    compress
    delaycompress
    notifempty
    create 0640 nginx adm
    sharedscripts
    postrotate
        [ -f /var/run/nginx.pid ] && kill -USR1 `cat /var/run/nginx.pid`
    endscript
}

完整监控配置示例：

nginx
user nginx;
worker_processes auto;

http {
    # 日志格式
    log_format main '$remote_addr - $remote_user [$time_local] '
                    '"$request" $status $body_bytes_sent '
                    '"$http_referer" "$http_user_agent"';
    
    log_format performance '$remote_addr - $remote_user [$time_local] '
                         '"$request" $status $body_bytes_sent '
                         'rt=$request_time '
                         'uct=$upstream_connect_time '
                         'uht="$upstream_header_time" '
                         'urt="$upstream_response_time" '
                         'cache=$upstream_cache_status';
    
    log_format json_combined escape=json '{'
        '"time_local":"$time_local",'
        '"remote_addr":"$remote_addr",'
        '"remote_user":"$remote_user",'
        '"request":"$request",'
        '"status":"$status",'
        '"body_bytes_sent":"$body_bytes_sent",'
        '"request_time":"$request_time",'
        '"http_referrer":"$http_referer",'
        '"http_user_agent":"$http_user_agent"'
    '}';
    
    # 主站点
    server {
        listen 80;
        server_name example.com;
        
        root /var/www/html;
        index index.html;
        
        # 性能日志
        access_log /var/log/nginx/performance.log performance;
        error_log /var/log/nginx/error.log warn;
        
        # 监控端点
        location /nginx_status {
            stub_status on;
            access_log off;
            allow 127.0.0.1;
            deny all;
        }
        
        location /health {
            access_log off;
            return 200 "OK\n";
            add_header Content-Type text/plain;
        }
        
        location /ready {
            access_log off;
            proxy_pass http://backend/health;
            proxy_intercept_errors off;
        }
        
        location /metrics {
            proxy_pass http://localhost:9113/metrics;
            access_log off;
            allow 127.0.0.1;
            deny all;
        }
        
        location / {
            proxy_pass http://backend;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }
    }
}

监控工具推荐：

Prometheus + Grafana：强大的监控和可视化平台
ELK Stack：日志收集、存储和分析
Zabbix：企业级监控系统
Nagios：成熟的监控解决方案
Datadog：云端监控服务
New Relic：应用性能监控
AppDynamics：应用性能管理

运维最佳实践：

全面监控：监控性能、日志、资源使用
及时告警：设置合理的告警阈值
定期备份：备份配置和重要数据
自动化运维：使用脚本和工具自动化运维
文档记录：详细记录运维操作和问题
定期演练：定期进行故障演练
性能优化：持续监控和优化性能
安全审计：定期进行安全检查
容量规划：根据业务增长进行容量规划
持续改进：根据监控数据持续改进