NGINX/uWSGI 负载下的反向代理 502 错误网关

Question

我正在使用 NGINX 作为 uWSGI 服务器的反向代理运行 Flask 应用程序。大多数请求都已成功处理，但在 500 个并发连接的负载测试后，一些请求（但不是全部！）被丢弃并出现 502 Bad Gateway 错误。

根据错误日志，似乎 NGINX 无法将连接发送到 uWSGI。然而，我不知道为什么会失败，因为我很容易运行 100 个 uWSGI 进程，每个进程都有 300 个监听积压。

我已经将 net.core.somaxconn 调整为 4096。我的 nginx.conf 看起来像这样：

    user www-data;
    worker_processes auto;
    pid /run/nginx.pid;
    include /etc/nginx/modules-enabled/*.conf;
    worker_rlimit_nofile 65535;

    events {
        worker_connections 65535;
        multi_accept on;
    }

    http {

    ##
    # Basic Settings
    ##

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    # server_tokens off;

    # server_names_hash_bucket_size 64;
    # server_name_in_redirect off;

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

    ##
    # SSL Settings
    ##

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
    ssl_prefer_server_ciphers on;

    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    ##
    # Gzip Settings
    ##

    gzip on;

    # gzip_vary on;
    # gzip_proxied any;
    # gzip_comp_level 6;
    # gzip_buffers 16 8k;
    # gzip_http_version 1.1;
    # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    ##
    # Virtual Host Configs
    ##

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;

    }

我的站点可用配置如下所示（将真正的 url 替换为 myservice.com）：

server {
server_name myservice.com www.myservice.com;
client_header_buffer_size 64k;
large_client_header_buffers 8 64k;

location / {
    include uwsgi_params;
    uwsgi_pass unix:/home/ubuntu/api_master/api.sock;
    client_max_body_size 500M;
}

listen 443 ssl backlog=65535; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/myservice.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/myservice.com/privkey.pem; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot




}
server {
if ($host = www.myservice.com) {
    return 301 https://$host$request_uri;
} # managed by Certbot


if ($host = myservice.com) {
    return 301 https://$host$request_uri;
} # managed by Certbot


listen 80;
server_name myservice.com www.myservice.com;
return 404; # managed by Certbot




}

不胜感激！如果我能在这台服务器上达到 4,096+ 个并发连接，那就太好了；我相信硬件可以处理它。

Answer 1

我建议您先尝试将 net.core.somaxconn 值乘以 4，然后看看情况是否会好转。否则，我会怀疑 multi_accept on; !

Answer 2

找到解决方案！事实证明这是 uWSGI 的问题，而不是 NGINX。我错误的假设是监听积压是每个进程，而不是汇总，增加该限制解决了问题。

NGINX/uWSGI 负载下的反向代理 502 错误网关

NGINX/uWSGI reverse proxy 502 Bad Gateway under load

nginx

flask

uwsgi

nginx-reverse-proxy

nginx-config