Magento Indexing and Caching

Overview

Magento's performance architecture relies on two distinct layers: indexers that pre-compute denormalized data (product prices, search indexes, category paths) into flat tables, and the Full-Page Cache (FPC) that stores complete rendered HTML pages. Varnish is the recommended FPC backend for production, replacing Magento's built-in file-based cache. Redis is the recommended backend for application cache, session storage, and the default cache (block HTML, config, layout). Misconfigured or stale indexes are one of the most common causes of incorrect pricing and product visibility issues.

When to Use This Skill

• When products appear with wrong prices or are invisible after catalog updates
• When implementing Varnish for the first time on a Magento production server
• When diagnosing slow category page loads caused by on-the-fly price calculation
• When configuring Redis for Magento's session and block cache storage
• When setting up cache invalidation after catalog or CMS updates via Magento's cache tags
• When managing indexer schedules on large catalogs (> 50,000 products) to prevent full reindex locking

Core Instructions

1. Understand Magento's indexers and their modes