Drupal Cache Debugging

Systematic approaches to identify and resolve caching issues.

When to Use

• Pages not caching for anonymous users
• X-Drupal-Dynamic-Cache shows UNCACHEABLE
• Content is stale after edits
• Need to find source of max-age:0
• Performance profiling cache effectiveness

Debug Headers Setup

// settings.local.php
$settings['http.response.debug_cacheability_headers'] = TRUE;