nginx.conf

user www-data;
pid /run/nginx.pid;

# Determine max possible open file count. # Hard # ulimit -Hn; # 65536.# Soft # ulimit -Sn; # 1024. # Set soft as  hard; # ulimit -n 65536;
worker_rlimit_nofile 65536; # ulimit

# you must set worker processes based on your CPU cores, nginx does not benefit from setting more than that
worker_processes auto; #some last versions calculate it automatically

events {
    worker_connections 65536; # ulimit

    # optmized to serve many clients with each thread, essential for linux -- for testing environment
    use epoll;

    # accept as many connections as possible, may flood worker connections if set too low -- for testing environment
    multi_accept on;
}

http {
    # copies data between one FD and other from within the kernel. # faster then read() + write()
    sendfile on;

    # send headers in one peace, its better then sending them one by one
    tcp_nopush on;

    # don't buffer data sent, good for small data bursts in real time
    tcp_nodelay on;

    keepalive_timeout 65;
    types_hash_max_size 2048;

    # keep track of every requested files for 2 minutes max, while expiring resources after 1 minute.
    open_file_cache max=500 inactive=20m;
    open_file_cache_valid 20m;

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

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

    log_format mycombined '$remote_addr - $remote_user [$time_local] ' '"$request" $status $body_bytes_sent ' '"$http_referer" "$http_user_agent"';
    access_log /var/log/nginx/access.log mycombined;
    error_log /var/log/nginx/error.log crit;

    # Will be included in each site from snippets/gzip.conf
    gzip off;

    # PHP Cache init settings. Does not mean that cache is being used.
    fastcgi_cache_path /tmp/cache_1h levels=1:2 keys_zone=cache_1h:100m max_size=100m inactive=1h;
    fastcgi_cache_path /tmp/cache_1h_auth levels=1:2 keys_zone=cache_1h_auth:100m max_size=100m inactive=1h;
    fastcgi_cache_path /tmp/cache_5m_auth levels=1:2 keys_zone=cache_5m_auth:100m max_size=100m inactive=5m;
    fastcgi_ignore_headers Cache-Control Expires Set-Cookie;
    fastcgi_cache_methods GET HEAD; # Only GET and HEAD methods apply

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