I wonder how I could improve the performance of my server? It is configured with Ubuntu 18.04 (LTS), 4 GB RAM, 100 GB SSD, 2 CPU, with Nginx 1.14.0 and PHP 7.2-fpm to handle running and serving a site that generates dynamic pages from a database. PHP has OP cache enabled. I would like to improve current setup without Varnish or proxy, just a plain Nginx with PHP setup.
Monitoring when load testing with 500 concurrent visitors, it reveals that CPU usage immediately jumps to 100% with PHP using the majority, 65% and SQL 15%. Memory usage is about 2,5Gb with 0,75Gb free and the swapfile untouched. When visiting the site during the test, there are 502 errors.
The logs, php7.2-fpm.log:
[12-May-2020 17:21:13] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 8 children, there are 0 idle, and 9 total children
[12-May-2020 17:21:14] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 16 children, there are 0 idle, and 10 total children
[12-May-2020 17:21:15] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 11 total childr
And in /var/log/nginx/error.log
2020/05/12 17:22:35 [error] 2936#2936: *25711 connect() to unix:/var/run/php/php7.2-fpm.sock failed (11: Resource temporarily unavailable) while connecting to upstream, client: [IPADDRESS], server: [DOMAINNAME], request: "GET /[URL] HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.2-fpm.sock:", host: "[HOSTNAME]"
Below are the configurations of Nginx and PHP
relevant settings in /etc/php/7.2/fpm/pool.d/www.conf:
listen = /run/php/php7.2-fpm.sock
pm = dynamic
pm.max_children = 150
pm.start_servers = 4
pm.min_spare_servers = 1
pm.max_spare_servers = 8
pm.max_requests = 250
/etc/nginx/nginx.conf:
user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;
events {
worker_connections 2048;
multi_accept off;
}
http {
##
# Basic Settings
##
sendfile on;
tcp_nopush on;
tcp_nodelay on;
types_hash_max_size 2048;
# server_tokens off;
client_body_buffer_size 10K;
client_header_buffer_size 1k;
client_max_body_size 100m;
large_client_header_buffers 4 8k;
fastcgi_buffers 16 16k;
fastcgi_buffer_size 32k;
client_body_timeout 12;
client_header_timeout 12;
keepalive_timeout 15;
send_timeout 10;
# 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;
# add_header Strict-Transport-Security "max-age=15768000; includeSubDomains" always;
##
# Logging Settings
##
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
##
# Gzip Settings
##
gzip on;
gzip_comp_level 2;
gzip_min_length 1000;
gzip_proxied expired no-cache no-store private auth;
gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
# 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/*;
}
/etc/nginx/sites-available/[SITENAME]:
server {
listen 443 ssl http2; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/[SITENAME]/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/[SITENAME]/privkey.pem; # managed by Certbot
#include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_ciphers EECDH+CHACHA20:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!MD5;
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
server_name [SITENAME];
root /home/[SITENAME]/domains/[SITENAME]/public_html/web;
index index.php index.html index.htm index.nginx-debian.html;
location / {
#try_files $uri $uri/ =404;
try_files $uri $uri/ /index.php?$query_string;
}
location ~ \.php$ {
include snippets/fastcgi-php.conf;
fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
}
}
server {
listen 443 ssl; # managed by Certbot
server_name [SITENAME];
return 301 https://[SITENAME]$request_uri;
ssl_certificate /etc/letsencrypt/live/[SITENAME]/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/[SITENAME]/privkey.pem; # managed by Certbot
}
server {
if ($host = [SITENAME]) {
return 301 https://$host$request_uri;
} # managed by Certbot
listen 80;
server_name [SITENAME];
return 404; # managed by Certbot
}
server {
listen 80;
if ($host = [SITENAME]) {
return 301 https://$host$request_uri;
} # managed by Certbot
server_name [SITENAME];
return 404; # managed by Certbot
}
