mysql - nginx 连接()失败(110 : Connection timed out)

Question

我知道，这个问题已经在不同的论坛上被问过多次，但我仍然无法找到解决方案来解决我的问题...情况:我们有 nginx、php-fpm 和 MySQL 堆栈在服务器上。服务器位于 nginx 反向代理后面。问题是，在上游服务器上有干净的错误日志，在反向代理上我收到多条消息

connect() failed (110: Connection timed out) while connecting to >upstream, client: ++++++++++, server: domain.com, request: "GET >/files/imagecache/FrontBullet/blog1/dknasda.jpg HTTP/1.1", upstream: >"http://192.168.158.142:80/files/imagecache/FrontBullet/blog1/dknasda.jpg>", host: "somedomain.com"

由于某种原因，对于不同的资源或文件，此错误每 1-5 分钟就会发生一次。

我在反向代理上的 nginx 配置如下:

    user ++++;
worker_processes 3;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

events {
    worker_connections 1024;
    use epoll;
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   60s; #keeps the connection open with the client; MS default is 60.
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    gzip on; 
    gzip_http_version 1.1; 
    gzip_vary on; 
    gzip_comp_level 6; 
    gzip_proxied any; 
    gzip_types text/plain  text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript application/javascript text/x-js; 
    gzip_buffers 16 8k; 
    gzip_disable "MSIE [1-6]\.(?!.*SV1)";

    upstream main_upstream {

        server 192.168.158.142:80 max_fails=3  fail_timeout=60s;  #       New Server. Sent to 192.168.90
#   server 192.168.158.143:80;   #       HSB
    keepalive 32;
    }

server {
    listen       80 default_server;
    listen       [::]:80 default_server;
    server_name  domain.com;

    location / {
        proxy_buffers 32 32k;
        proxy_buffer_size 64k;
        proxy_pass http://main_upstream;
        proxy_set_header    Host $host;
        proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header    X-Forwarded-Proto $scheme;
        proxy_set_header    X-Forwarded-By $server_addr:$server_port;
            proxy_set_header    X-Real-IP $remote_addr;
        proxy_connect_timeout       600s;
        proxy_send_timeout          600s;
        proxy_read_timeout          600s;
        send_timeout                600s;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
        client_max_body_size                            32M;
        client_body_buffer_size                         512k;
    }
    error_page 404 /404.html;
        location = /40x.html {
    }

    error_page 500 502 503 504 /50x.html;
        location = /50x.html {
    }
}

知道为什么会发生这种情况吗？我使用的是centos 7.1 abd nginx 1.6.3

提前致谢，托多尔

Answer 1

终于找到原因了，几个小时以来它已经干净了。结果发现有两个重叠的问题。第一个是内核在队列已满后丢弃请求。这是一本关于调整内核 Linux 内核参数的好手册 - https://www.nginx.com/blog/tuning-nginx/

问题出现后，我们将站点迁移到新服务器并使用 DHCP 分配 IP 地址 - 这是一个大错误。大约每隔一小时，dhcp 就会重新启动网络接口(interface)。检查整个系统日志，我注意到网络接口(interface)的 IP 会定期重新分配。这些间隔与日志中的错误爆发一致。所以解决方案是回到静态 IP。