PHP Redis — Uniform TTLs Caused Black Friday Cache Stampede

<?php
/**
 * io.thecodeforge: Standardized Redis Connection Implementation
 */

$redis = new Redis();

// Use pconnect for persistent connections in high-traffic environments
try {
    $redis->pconnect('127.0.0.1', 6379, 2.5); // 2.5s timeout
    $redis->setOption(Redis::OPT_SERIALIZER, Redis::SERIALIZER_PHP);
    $redis->setOption(Redis::OPT_PREFIX, 'forge_app:'); 
} catch (RedisException $e) {
    // Log error and fallback to database or static cache
    error_log("Redis Connection Failed: " . $e->getMessage());
}

<?php
namespace io\thecodeforge\cache;

class CacheAside
{
    private \Redis $redis;
    private \PDO $db;
    
    public function getUser(int $userId): array
    {
        $key = "user:{$userId}";
        
        // Check Redis first
        $cached = $this->redis->get($key);
        if ($cached !== false) {
            return unserialize($cached); // or Redis::SERIALIZER_PHP handles this
        }
        
        // Cache miss — fetch from database
        $stmt = $this->db->prepare('SELECT * FROM users WHERE id = ?');
        $stmt->execute([$userId]);
        $user = $stmt->fetch(\PDO::FETCH_ASSOC);
        
        if ($user) {
            // Store in Redis with 10-minute TTL
            $this->redis->setex($key, 600, serialize($user));
        }
        
        return $user ?: [];
    }
    
    public function updateUser(int $userId, array $data): void
    {
        // Update database
        $stmt = $this->db->prepare('UPDATE users SET name = ? WHERE id = ?');
        $stmt->execute([$data['name'], $userId]);
        
        // Invalidate cache
        $this->redis->del("user:{$userId}");
    }
}

<?php
namespace io\thecodeforge\ratelimit;

class RateLimiter
{
    private \Redis $redis;
    private int $maxRequests;
    private int $windowSeconds;
    
    public function __construct(\Redis $redis, int $maxRequests = 100, int $windowSeconds = 60)
    {
        $this->redis = $redis;
        $this->maxRequests = $maxRequests;
        $this->windowSeconds = $windowSeconds;
    }
    
    public function isAllowed(int $userId): bool
    {
        $key = "rate_limit:{$this->windowSeconds}:{$userId}";
        
        // Atomic INCR followed by conditional expiry
        $current = $this->redis->incr($key);
        
        if ($current === 1) {
            // First request — set expiry atomically (INCR does not support EXPIRE in one command)
            $this->redis->expire($key, $this->windowSeconds);
        }
        
        return $current <= $this->maxRequests;
    }
    
    // Alternatively, use a single SET NX with EX to avoid race condition entirely
}

; io.thecodeforge: Production Redis Session Handler
session.save_handler = redis
session.save_path = "tcp://127.0.0.1:6379?auth=yourpassword&prefix=PHPREDIS_SESSION:"
session.gc_maxlifetime = 86400
session.serialize_handler = php_serialize

<?php
namespace io\thecodeforge\pubsub;

class EventPublisher
{
    private \Redis $redis;
    
    public function __construct(\Redis $redis)
    {
        $this->redis = $redis;
    }
    
    public function publishOrderPlaced(int $orderId, array $orderData): int
    {
        $message = json_encode([
            'event' => 'order.placed',
            'order_id' => $orderId,
            'timestamp' => time(),
            'data' => $orderData
        ]);
        
        return $this->redis->publish('forge_events', $message);
    }
}

<?php
namespace io\thecodeforge\bulk;

class BulkImport
{
    private \Redis $redis;
    
    public function importProducts(array $products): array
    {
        // Start pipelining
        $pipe = $this->redis->pipeline();
        
        foreach ($products as $product) {
            $key = "product:{$product['id']}";
            $pipe->hMSet($key, $product);
            $pipe->expire($key, 3600);
        }
        
        // Execute all commands atomically (as a batch)
        $results = $pipe->exec();
        
        return $products;
    }
    
    // Without pipeline: 1 second for 1000 operations
    // With pipeline: ~5ms for 1000 operations — 200x improvement
}

# io.thecodeforge: Optimized PHP-Redis Runtime
FROM php:8.2-fpm-alpine

# Install the high-performance phpredis extension
RUN apk add --no-cache pcre-dev $PHPIZE_DEPS \
    && pecl install redis \
    && docker-php-ext-enable redis

WORKDIR /var/www/html
COPY . .

-- io.thecodeforge: Analytics for Cache Efficiency
CREATE TABLE io.thecodeforge.cache_performance (
    id SERIAL PRIMARY KEY,
    cache_key_prefix VARCHAR(50),
    hits BIGINT DEFAULT 0,
    misses BIGINT DEFAULT 0,
    avg_latency_ms DECIMAL(5,2),
    recorded_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

package io.thecodeforge.redis;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPubSub;

/**
 * io.thecodeforge: Java Backend listening for PHP events
 */
public class PubSubListener {
    public static void main(String[] args) {
        try (Jedis jedis = new Jedis("localhost", 6379)) {
            System.out.println("Forge Worker: Listening for PHP events...");
            jedis.subscribe(new JedisPubSub() {
                @Override
                public void onMessage(String channel, String message) {
                    System.out.println("Received from PHP: " + message);
                }
            }, "forge_events");
        }
    }
}