What factors are contributing to the increased page load times for Pantheon-hosted Drupal sites in the last two weeks?

Introduction

The recent increase in page load times for Pantheon-hosted Drupal sites is a critical issue that demands immediate attention. As we delve into this problem, we'll systematically analyze potential causes, validate hypotheses, and develop a comprehensive solution strategy. Our approach will encompass both technical and user-centric perspectives to ensure a holistic understanding of the issue.

Step 1

Clarifying Questions (3 minute)

• Looking at the timing, I'm thinking there might have been a recent platform update. Has Pantheon rolled out any changes to their hosting infrastructure in the last two weeks?

Why it matters: Platform changes could directly impact page load times. Expected answer: Yes, there was a minor update to the caching layer. Impact on approach: If confirmed, we'd focus on the caching system as a primary area of investigation.

• Considering the specificity to Drupal sites, I'm wondering about content management patterns. Have there been any significant changes in how content is being managed or published on these sites recently?

Why it matters: Changes in content management could affect database queries and overall site performance. Expected answer: No major changes reported by site administrators. Impact on approach: If true, we'd shift focus to backend performance issues rather than content-related causes.

• Given the widespread nature of the issue, I'm curious about traffic patterns. Have you noticed any unusual spikes or changes in traffic to these Drupal sites over the past two weeks?

Why it matters: Unexpected traffic surges could strain server resources and increase load times. Expected answer: Traffic has remained relatively consistent. Impact on approach: If confirmed, we'd rule out traffic-related causes and focus on internal system issues.

• Thinking about the Drupal ecosystem, I'm considering plugin updates. Has there been a common Drupal plugin update across many of these affected sites?

Why it matters: A problematic plugin update could cause widespread performance issues. Expected answer: Several sites updated a popular caching plugin two weeks ago. Impact on approach: This would lead us to investigate the specific plugin and its interactions with Pantheon's infrastructure.