[Performance Regression] Severe price calculation latency in 2.4.8-p4 related to Weee Plugin and Configurable Products #40642
Description
Preconditions and environment
Following our upgrade from Magento 2.4.7-p8 to 2.4.8-p4, we are experiencing a critical performance degradation specifically during price rendering on Category Listing Pages (PLP) and Search results.
Steps to reproduce
Core Discovery:
Our performance profiling (Blackfire & New Relic) highlights that 30.5% of the total execution time is consumed by price computing, specifically:
Magento\Framework\Pricing\Adjustment\Calculator::getAmount
Total time in trace: 1524105 ms (Cumulative).
Suspected Root Cause:
We have identified a new Plugin introduced in Magento 2.4.8:
Magento\Weee\Plugin\Model\ConfigurableVariationAttributePriority.
This plugin appears to trigger redundant parent product loads and repetitive WEEE attribute lookups for every child product of a configurable, leading to a massive increase in SQL queries and CPU usage during the getFinalPrice cycle. In our environment, this results in a "N+1" query problem that didn't exist in 2.4.7.
Impact:
TTFB: Increased significantly.
SEO: Massive drop in crawl budget due to page latency.
Could you please confirm if this new WEEE Plugin has known performance issues with large catalogs or configurable products? We need a fix or a recommended patch to optimize how price adjustments are calculated in this version.
Expected result
Pricing Efficiency: The time allocated to Magento\Framework\Pricing\Adjustment\Calculator::getAmount should not exceed 5% to 10% of total execution time, down from the current 30.5%.
Optimized WEEE Logic: WEEE attribute and tax calculations for configurable products should be optimized (via static caching or indexing) to avoid reloading the parent product object during every variant iteration.
TTFB Stability: Price rendering performance should be equivalent to or better than 2.4.7-p8 without major regressions introduced by new tax calculation plugins.
Scalability: The system must handle product listings without the CPU cost of price calculations growing exponentially based on the number of simple variants attached to configurables.
Actual result
N+1 Price Complexity: Rendering a page with 32 configurable products triggers a disproportionate volume of unit price calculations, consuming 30.5% of total CPU time (~1.5s of pure calculation per request).
WEEE Plugin Overhead: The profiler identifies the ConfigurableVariationAttributePriority plugin as a major bottleneck, causing redundant parent object hydrations for every simple variant displayed.
TTFB Degradation: Server response time (Wall Time) has spiked significantly since the 2.4.8-p3 update, making Category Listing Pages (PLP) unstable and slow.
SEO Impact: Excessive latency has caused a massive drop in the Crawl Budget as search engine bots encounter increased response delays.
Additional information
No response
Release note
No response
Triage and priority
- Severity: S0 - Affects critical data or functionality and leaves users without workaround.
- Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
- Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
- Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
- Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.