woocommerce-performance

WooCommerce Performance

Overview

WooCommerce performance problems typically stem from five sources: expensive product queries with un-indexed meta tables, unbounded AJAX cart/checkout calls, missing persistent object cache, bloated wp_options autoload data, and a growing wp_woocommerce_sessions and order table without cleanup. This skill covers profiling, query optimization, Redis object caching, and scheduled maintenance routines.

When to Use This Skill

• When store pages are slow to load under moderate traffic (hundreds of concurrent users)
• When server CPU spikes during WooCommerce AJAX calls (add-to-cart, shipping calculation)
• When MySQL query time shows in New Relic or Query Monitor as the primary bottleneck
• When the wp_options table autoload size exceeds 1–2 MB
• When wp_woocommerce_sessions has millions of rows slowing down session lookups
• When implementing Redis or Memcached to reduce MySQL load on a high-traffic store

Core Instructions

1. Profile first with Query Monitor

   Install Query Monitor plugin to identify slow queries in the admin and frontend:

   # Via WP-CLI
   wp plugin install query-monitor --activate
   

   Focus on:

   • Queries per page load (> 50 is a concern)
   • Duplicate queries (same query run multiple times)
   • Slow queries (> 100ms individual queries)
   • Large result sets (queries returning thousands of rows)

   For production profiling, enable MySQL slow query log:

   SET GLOBAL slow_query_log = 'ON';
   SET GLOBAL long_query_time = 0.5;
   SET GLOBAL slow_query_log_file = '/var/log/mysql/slow.log';
   

2. Enable Redis persistent object cache

   The single highest-impact optimization for WooCommerce. Without it, every page load re-fetches the same product data from MySQL:

   # Install Redis server
   sudo apt install redis-server
   
   # Install the Redis Object Cache plugin
   wp plugin install redis-cache --activate
   wp redis enable
   

   Configure in wp-config.php: