Redis: Benchmark, Tuning e Configurazione su Ubuntu

<?php
// benchmark_redis.php
// Esegui: php benchmark_redis.php

// Installa predis se non lo hai: composer require predis/predis
require 'vendor/autoload.php';

$host = '127.0.0.1';
$user = 'benchmark';
$pass = 'benchmark';
$db   = 'benchmark';

// Connessione al database
try {
    $pdo = new PDO("mysql:host=$host;dbname=$db;charset=utf8", $user, $pass);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
    die("Errore di connessione al database: " . $e->getMessage());
}

// Connessione a Redis
try {
    $redis = new Predis\Client([
        'scheme' => 'tcp',
        'host'   => '127.0.0.1',
        'port'   => 6379,
    ]);
    $redis->ping(); // Verifica che Redis risponda
    echo "✅ Connessione a Redis stabilita.\n\n";
} catch (Exception $e) {
    die("Errore di connessione a Redis: " . $e->getMessage());
}

// Le stesse 5 query di prima
$queries = [
    'Conteggio per stato' => "SELECT status, COUNT(*) as total FROM orders GROUP BY status",
    'Vendite per mese' => "SELECT DATE_FORMAT(order_date, '%Y-%m') as month, SUM(price * quantity) as total FROM orders GROUP BY month ORDER BY month DESC",
    'Top 10 clienti' => "SELECT customer_name, SUM(price * quantity) as total_spent FROM orders GROUP BY customer_name ORDER BY total_spent DESC LIMIT 10",
    'Ricerca per email' => "SELECT * FROM orders WHERE customer_email LIKE '%marco.rossi%'",
    'Statistiche mensili' => "SELECT DATE_FORMAT(order_date, '%Y-%m') as month, COUNT(*) as orders, SUM(price * quantity) as revenue, AVG(price * quantity) as avg_order_value FROM orders GROUP BY month ORDER BY month DESC"
];

// Funzione che esegue la query con cache
function executeWithCache($pdo, $redis, $sql, $cacheKey) {
    // Prova a leggere dalla cache
    $cached = $redis->get($cacheKey);
    
    if ($cached !== null) {
        // Cache hit: restituisci i dati dalla cache
        return [
            'cached' => true,
            'data' => json_decode($cached, true)
        ];
    }
    
    // Cache miss: esegui la query sul database
    $start = microtime(true);
    $result = $pdo->query($sql)->fetchAll();
    $queryTime = (microtime(true) - $start) * 1000;
    
    // Salva in Redis con scadenza di 60 secondi
    $redis->setex($cacheKey, 60, json_encode($result));
    
    return [
        'cached' => false,
        'data' => $result,
        'query_time' => $queryTime
    ];
}

$iterations = 100;
$results = [];

echo "Esecuzione benchmark CON Redis (caching)...\n";
echo "Query eseguite $iterations volte ciascuna.\n";
echo "(Prima esecuzione: cache miss, successive: cache hit)\n\n";

foreach ($queries as $name => $sql) {
    $times = [];
    $cacheKey = 'benchmark_' . md5($sql);
    
    // Svuota la cache prima del test
    $redis->del($cacheKey);
    
    for ($i = 0; $i < $iterations; $i++) {
        $start = microtime(true);
        $result = executeWithCache($pdo, $redis, $sql, $cacheKey);
        $end = microtime(true);
        $times[] = ($end - $start) * 1000;
    }
    
    $avg = array_sum($times) / count($times);
    $min = min($times);
    $max = max($times);
    
    // Calcola separatamente la prima esecuzione (cache miss)
    $first = $times[0];
    
    $results[$name] = [
        'avg' => $avg,
        'min' => $min,
        'max' => $max,
        'first' => $first
    ];
    
    echo "🔹 $name\n";
    echo "   Prima esecuzione (cache miss): " . number_format($first, 2) . " ms\n";
    echo "   Media (con cache): " . number_format($avg, 2) . " ms\n";
    echo "   Min:   " . number_format($min, 2) . " ms\n";
    echo "   Max:   " . number_format($max, 2) . " ms\n\n";
}

// Salva i risultati per il confronto
file_put_contents('redis_results.json', json_encode($results, JSON_PRETTY_PRINT));
echo "✅ Risultati salvati in redis_results.json\n";