Drupal 11.3.0: Biggest performance boost in a decade

Drupal 11.3 includes a number of significant performance improvements, altogether making it the most significant step forward for Drupal performance in the last 10 years (since the Drupal 8.0.0 release).

These improvements have been driven by enhancements to Drupal's render and caching layers in 11.2.x, notably taking advantage of Fibers, a new PHP feature added in PHP 8.1. By rendering more parts of the page in placeholders, we have enabled similar database and cache operations that used to occur individually to be combined, with particular improvements in path alias and entity loading. We have also learned from Drupal's automated performance testing framework, allowing us to identify and execute several optimizations during Drupal's hook and field discovery processes, to significantly reduce database and cache i/o, and memory usage on cold caches.

On the front end we have converted Drupal's BigPipe implementation to use HTMX, reducing JavaScript weight significantly. We also intercept placeholders with warm render caches prior to BigPipe replacement, so that BigPipe's JavaScript is not loaded at all on requests that will be served quickly without it, allowing BigPipe to be used more widely for the requests that do need it. These changes may also allow us to enable BigPipe for anonymous site visitors in a future release.

Combined, these changes reduce database query and cache operations on cold cache requests by around one third, with smaller but still significant improvements when caches become warmer, up to and including dynamic and internal page cache hits.

Drupal's automated performance tests show many of these improvements, and will ensure that we continue to build and maintain on these gains over time.

Drupal Umami demo’s anonymous cold cache front page request

Let's look at an example. These are the changes in Drupal core's included Umami demo's anonymous cold cache front page request performance test between 11.2.x and 11.3.x.

Particularly notable is the benefit for requests to pages with partially warmed caches, where site-wide caches are full, but page-specific caches are invalid or empty. In core's performance test for this scenario, we saw an almost 50% reduction in database queries. Requests like this make up a large percentage of the slowest responses from real Drupal sites, and core now provides a much lower baseline to work against. Medium to large sites often hit constraints with the database first, because it is harder to scale than simply adding webservers, and these improvements reduce load when it is at its most constrained.

Drupal Umami demo’s anonymous node page with partially-warmed cache

While different sites, and even different pages on the same site, will show different results, we would expect all Drupal sites to see a significant reduction in database and cache i/o per request once they've updated to Drupal 11.3.

Independent testing and further improvements with Paragraphs

Independent testing by MD Systems on their internal Primer Drupal distribution shows even better improvements with Drupal 11.3, especially for complex pages. This is also thanks to further improvements enabled and inspired by Drupal 11.3 in the Entity Reference Revisions module which resulted in considerable performance improvements for Paragraphs. Their results show a dramatic reduction in database and cache operations across different cache states. Their cold cache total query count dropped by 62% (from 1097 to 420), and total cache lookups decreased by 47% (from 991 to 522) compared to Drupal 11.2. At the same time their partially-warm cache total query count dropped by 61% (from 696 to 274) and total cache lookups decreased by 34% (from 562 to 373).

Even more technical details

For further details on how these improvements happened, check out some of the core issues that introduced them, or watch Nathaniel Catchpole's DrupalCon Vienna presentation.

#1237636: Lazy load multiple entities at a time using fibers
#2620980: Add static and persistent caching to ContentEntityStorageBase::loadRevision()
#3496369: Multiple load path aliases without the preload cache
#3537863: Optimize field module's hook_entity_bundle_info() implementation
#3538006: Optimize EntityFieldManager::buildBundleFieldDefinitions()
#3526080: Reduce write contention to the fast and consistent backend in ChainedFastBackend
#3493911: Add a CachedPlaceholderStrategy to optimize render cache hits and reduce layout shift from big pipe
#3526267: Remove core/drupal.ajax dependency from big_pipe/big_pipe
#3506930: Separate hooks from events
#3505248: Ability to preload frequently used cache tags (11.2.x)

There is more to do for Drupal 11.4!

If you'd like to help 11.4 become even faster yet, check out core issues tagged with 'performance' and try to help us get them done. We have multiple issues in progress that didn't quite make it into 11.3.0 but could form the basis of another significant set of improvements in 11.4.0.