NGINX/PM2

nginx.conf

worker_processes  auto;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    tcp_nodelay     on;

    types_hash_max_size 2048;
    server_names_hash_bucket_size 64;

    client_body_timeout             60;
    client_header_timeout           60;
    keepalive_timeout            10 10;
    send_timeout                    60;

    client_max_body_size          128M;

    client_header_buffer_size    1k;
    large_client_header_buffers  4 4k;

    gzip on;
    gzip_http_version 1.1;
    gzip_comp_level 5;
    gzip_vary on;
    gzip_proxied any;
    gzip_min_length  10;
    gzip_buffers 16 8k;
    gzip_types text/plain text/css application/json application/x-javascript text/javascript image/png image/gif image/x-icon;
    gzip_disable "MSIE [1-6].(?!.*SV1)";

    upstream vsapi {
        server 127.0.0.1:3010;
        keepalive 64;
    }

    server {
        listen 443 ssl http2;

	      ssl    on;
	      ssl_certificate    /etc/ssl/XXX.crt;
	      ssl_certificate_key    /etc/ssl/YYY.key;

        ssl_session_cache shared:SSL:20m;
        ssl_session_timeout 10m;

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

        add_header Strict-Transport-Security "max-age=31536000; includeSubDomain";

	      ssl_prefer_server_ciphers   on;

        server_name *;
        keepalive_timeout 10;

        location /api {
            proxy_redirect     off;
            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_set_header   Host                   $http_host;
            proxy_set_header   X-NginX-Proxy    true;
            proxy_set_header   Connection "";
            proxy_pass         http://vsapi;
        }
    }
}

I'm getting socket leaks with a similar configuration. How is this working out for you?