### **_A complete blueprint for load testing Magento using JMeter, k6, Locust, Gatling, Adobe Commerce Site-Wide Analysis Tool, New Relic, synthetic monitoring, and real-world traffic simulation._** # **1. Introduction — Why Load Testing Matters in Magento (2025)** Most Magento sites break ONLY under pressure. Without load testing, you don’t know: - If checkout will survive peak traffic - If Redis will handle heavy sessions - If database can handle high concurrency - If Elasticsearch queries will fail - If queue consumers will backlog - If TTFB will spike - If price rules will slow down orders - If Fastly caching is efficient Load testing ensures: - Predictable scalability - Zero downtime - Stable checkout - Stable cart flow - Safe deployments - High conversion during sale events This guide is your **complete 2025 Magento load testing handbook**. # **2. Types of Load Tests for Magento** Different tests serve different purposes. ### **2.1 Load Test** Gradual traffic increase to measure capacity. ### **2.2 Stress Test** Push beyond limit until system breaks. ### **2.3 Spike Test** Sudden traffic burst (Black Friday behavior). ### **2.4 Soak Test (Endurance)** Long-running test (1–4 hours). ### **2.5 Scalability Test** Test horizontal scaling behavior. ### **2.6 Checkout Journey Test** Simulate real user checkout. ### **2.7 API Performance Test** Especially for: - GraphQL - Cart APIs - Checkout APIs # **3. Load Testing Tools Recommended for Magento (2025)** ## **✔ JMeter (most commonly used)** Best for: - Checkout journey - Cart/PLP/PDP flows - Multi-step transactional flows ## **✔ k6 (modern, cloud-ready)** Best for: - Checkout APIs - GraphQL - Checkout V2 - Headless storefronts ## **✔ Locust (Python-based)** Best for: - Realistic user journeys - Distributed tests ## **✔ Gatling** Best for: - Extremely high RPS - Cloud simulation ## **✔ Adobe Commerce SWAT + New Relic** Best for: - Adobe Commerce Cloud - Real-time bottleneck analysis ![Load Test Architecture Diagram](https://res.cloudinary.com/dnd6owhkg/image/upload/v1764133683/docx-images/tfywx4f7w5ibkcyprel0.png) # **4. Components to Monitor During Magento Load Testing** During testing, track **all layers**: ### **Frontend** - LCP - INP - TTFB - Page load time ### **Backend** - PHP-FPM queue - Redis latency - DB connections - ES latency - Queue backlog - CPU/RAM ### **CDN** - Fastly HIT ratio - Edge latency - Bandwidth usage ### **APM Tools** - New Relic APM - Datadog - Grafana + Prometheus - Elastic Logs # **5. Realistic Load Testing Scenarios for Magento** These simulate actual user behavior. ## **5.1 Homepage → PLP → PDP → Add to Cart → Checkout** Simulates eCommerce shopper behavior. ### **Steps:** 1. Load homepage 2. Load category page 3. Load PLP filters 4. Load PDP 5. Add to cart 6. Trigger mini cart 7. Checkout shipping 8. Checkout payment 9. Place order This is the **single most important Magento load test**. ## **5.2 Cart API Load Test** Hit: - /rest/V1/guest-carts - /rest/V1/carts/mine - /rest/V1/carts/*/totals Important because cart APIs fail under pressure. ## **5.3 Checkout API Load Test** Test: - /shipping-information - /payment-information - Order submission Also test payment provider APIs (Stripe, PayPal, Adyen). ## **5.4 Search & PLP Load** Test: - Category filters - Search suggestions - Search result pages This fully loads Elasticsearch under stress. ![JMeter Checkout Flow](https://res.cloudinary.com/dnd6owhkg/image/upload/v1764133685/docx-images/tdqxrsmssqhjv3ejhrdm.png) # **6. Key Performance Metrics & Thresholds (2025 Standards)** A Magento store must meet these: ### **Server-Side Metrics** - TTFB < **500ms** under load - Redis latency < **5ms** - ES query < **15–20ms** - DB query < **100ms** avg - PHP-FPM queue < **20** - CPU < **70%** sustained - Queue backlog < **200 messages** ### **Client-Side Metrics** - LCP < **1.5s** - INP < **150ms** - CLS < **0.05** - Time to Interactive < **3s** ### **Concurrency Levels** - Mid-size brand: **300–600 concurrent** - Enterprise: **1,000–5,000 concurrent** - Global brand: **8,000+ concurrent** # **7. Common Failure Points Found During Magento Load Testing** ### **❌ 1. Redis Saturation** Session writes too large. ### **❌ 2. Slow Elasticsearch** Heap memory 95%. ### **❌ 3. Database deadlocks** Especially on carts and orders. ### **❌ 4. Quote table contention** Typical issue during add-to-cart flood. ### **❌ 5. Checkout “Place Order” delays** Payment integrations slow. ### **❌ 6. Price rules slow** Cart rules slow down totals updates. ### **❌ 7. Cache MISS storms** Fastly/Varnish MISS causes backend overload. ### **❌ 8. Queue backlog** Consumers can’t keep up. ### **❌ 9. GraphQL meltdown** Large responses or expensive queries kill ES. ### **❌ 10. External APIs failing under load** Shipping, tax, fraud checks. # **8. How to Prepare Magento for Load Testing** ### **✔ Freeze deployments** ### **✔ Disable admin access** ### **✔ Clone production data (sanitize emails)** ### **✔ Enable maintenance mode for bots** ### **✔ Disable all real payment integrations** ### **✔ Reduce logging to avoid noise** ### **✔ Monitor New Relic during tests** ### **✔ Warm cache before test** ### **Pre-warm endpoints:** - Home - PLP - PDP - Cart - Checkout Warm 300–500 URLs using a crawler. # **9. Stages of Running a Proper Magento Load Test** ### **Stage 1: Baseline Test** Low RPS to measure baseline performance. ### **Stage 2: Progressive Load** Increase traffic gradually. 10 → 50 → 200 → 500 → 1000 users ### **Stage 3: Stress Threshold** Push until the system starts failing. Signs: - 503 errors - Slow TTFB - Redis spikes - ES timeouts - DB lock waits ### **Stage 4: Soak Test** Run moderate load for 60–180 minutes. This finds: - Memory leaks - Slow cleanup - Queue saturation - Redis fragmentation ### **Stage 5: Spike Test** Simulate Black Friday sudden surge. 200 users → 2000 users instantly # **10. Reporting Load Test Results** A proper test report must include: ### **✔ Success/Failure rate** ### **✔ Avg / p95 / p99 latency** ### **✔ Concurrency handled** ### **✔ CPU/memory usage** ### **✔ Redis latency graphs** ### **✔ ES heap & GC cycles** ### **✔ DB slow queries** ### **✔ Queue backlog graph** ### **✔ API failures per minute** ![Load Test Results](https://res.cloudinary.com/dnd6owhkg/image/upload/v1764133687/docx-images/errulngnf8mcphdpn75w.png) # **11. Real-World Case Study — USA Electronics Mega Retailer** ### **Before test:** - Max concurrent: 300 - Redis latency: 24ms - ES heap: 95% - DB deadlocks frequent - Queue backlog: 4800 messages - TTFB: 2.5s under load ### **After improvements:** - Redis split - ES cluster upgrade - Checkout API optimizations - Queue concurrency increased - Cache HIT ratio improved ### **After test:** - Supported 3,500 concurrent users - Redis latency < 3ms - TTFB: 480–650ms - 0% error rate - Checkout stable # **Conclusion** Load testing is **mandatory** for any Magento store expecting growth, seasonal traffic, or marketing campaigns. With structured testing: - No surprises during sales - No downtime - Checkout stays smooth - Redis stays stable - DB remains healthy - Elastic doesn’t choke - Conversion rate stays high