Certainly! Optimizing PHP for high-traffic websites requires a comprehensive approach that spans code quality, database management, caching, server configuration, and much more. Below is an extensive list of rules to optimize PHP for high-traffic websites, with hands-on examples included where applicable.
1. Use Opcode Caching
Rule: Enable OPcache to cache precompiled PHP code.
Example:
; Enable OPcache in php.ini
opcache.enable=1
opcache.memory_consumption=128
opcache.interned_strings_buffer=8
opcache.max_accelerated_files=10000
opcache.revalidate_freq=60
2. Optimize Database Queries
Rule: Use indexed columns and avoid unnecessary columns in SELECT statements.
Example:
-- Instead of SELECT *
SELECT id, name, price FROM products WHERE category_id = 1;
3. Implement Data Caching
Rule: Cache frequently accessed data with Memcached.
Example:
$memcached = new Memcached();
$memcached->addServer('localhost', 11211);
$key = 'products_list';
$products = $memcached->get($key);
if ($products === FALSE) {
$products = get_products_from_database(); // Fetch from DB
$memcached->set($key, $products, 600); // Cache for 10 minutes
}
4. Use Persistent Connections
Rule: Use persistent database connections to reduce connection overhead.
Example:
$pdo = new PDO('mysql:host=localhost;dbname=test', 'user', 'password', [
PDO::ATTR_PERSISTENT => true
]);
5. Reduce File I/O Operations
Rule: Minimize file system reads/writes.
Example:
// Avoid repeated file reads
$settings = include('config.php'); // Cache this in a variable if used multiple times
6. Optimize PHP Configuration
Rule: Adjust php.ini
settings for better performance.
Example:
memory_limit=256M
max_execution_time=30
7. Use Autoloaders
Rule: Use Composer's autoloader for efficient class loading.
Example:
require 'vendor/autoload.php'; // Composer's autoloader
// Use classes
$object = new MyClass();
8. Implement Load Balancing
Rule: Distribute traffic across multiple servers.
Example:
- Configure Nginx for load balancing:
http {
upstream backend {
server backend1.example.com;
server backend2.example.com;
}
server {
location / {
proxy_pass http://backend;
}
}
}
9. Use Asynchronous Processing
Rule: Offload tasks to background processes.
Example:
// Using a queue system like Redis
$redis = new Redis();
$redis->connect('localhost');
$redis->rPush('email_queue', json_encode($emailData));
// Worker process to handle email sending
$emailData = json_decode($redis->lPop('email_queue'), true);
send_email($emailData);
10. Minimize Dependencies
Rule: Only include necessary libraries and dependencies.
Example:
composer install --no-dev // Install production dependencies only
11. Optimize Loops and Algorithms
Rule: Avoid inefficient loops and algorithms.
Example:
// Instead of inefficient loops
foreach ($items as $item) {
// Process item
}
// Use optimized algorithms and data structures
$items = array_map('processItem', $items);
12. Use Efficient Data Structures
Rule: Choose appropriate data structures for your needs.
Example:
// Using associative arrays for quick lookups
$data = ['key1' => 'value1', 'key2' => 'value2'];
$value = $data['key1'];
13. Optimize Session Handling
Rule: Use efficient session storage.
Example:
; Use Redis for session storage
session.save_handler = redis
session.save_path = "tcp://localhost:6379"
14. Use HTTP/2
Rule: Take advantage of HTTP/2 for better performance.
Example:
- Configure HTTP/2 in Nginx:
server {
listen 443 ssl http2;
# Other SSL configuration
}
15. Implement Gzip Compression
Rule: Compress responses to reduce bandwidth.
Example:
- Enable Gzip in Nginx:
http {
gzip on;
gzip_types text/plain text/css application/json application/javascript;
}
16. Minimize Frontend Asset Size
Rule: Optimize CSS, JavaScript, and image files.
Example:
# Minify CSS and JS files
uglifyjs script.js -o script.min.js
17. Use a Content Delivery Network (CDN)
Rule: Offload static content to a CDN.
Example:
- Configure CDN for static assets:
<link rel="stylesheet" href="https://cdn.example.com/styles.css">
<script src="https://cdn.example.com/scripts.js"></script>
18. Enable Error Logging
Rule: Log errors efficiently for debugging.
Example:
; Log errors to a file
error_log = /var/log/php_errors.log
log_errors = On
19. Monitor Performance
Rule: Use monitoring tools to track performance.
Example:
- Install and configure New Relic:
# Install New Relic PHP agent
sudo newrelic-install install
# Configure New Relic in php.ini
newrelic.enabled = true
20. Regularly Profile and Benchmark
Rule: Continuously profile and benchmark your application.
Example:
- Use Xdebug to profile PHP scripts:
# Install Xdebug
sudo pecl install xdebug
# Enable Xdebug profiling in php.ini
xdebug.profiler_enable = 1
xdebug.profiler_output_dir = "/tmp/xdebug"
By following these rules and implementing the provided examples, you can significantly enhance the performance and scalability of PHP-based high-traffic websites.