What caused the sudden spike in error rates for Looker's LookML validation process last week?

Introduction

The sudden spike in error rates for Looker's LookML validation process last week is a critical issue that demands immediate attention. As we delve into this product execution problem, we'll employ a systematic approach to identify, validate, and address the root cause while considering both short-term fixes and long-term strategic implications.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking this might be related to a recent deployment. Has there been any significant update to the LookML validation process or related systems in the past week?

Why it matters: Recent changes often correlate with sudden performance shifts. Expected answer: Yes, there was a deployment last Tuesday. Impact on approach: If confirmed, we'd focus on changes in that deployment.

• Considering the nature of the issue, I'm wondering about the scale. What percentage increase in error rates are we seeing compared to the baseline?

Why it matters: The magnitude helps prioritize the issue and narrow down potential causes. Expected answer: A 200% increase in error rates. Impact on approach: A large increase might indicate a systemic issue rather than an edge case.

• Given that this is a validation process, I'm curious about the types of errors. Are we seeing a specific type of error dominating the increase, or is it across the board?

Why it matters: This helps identify if the issue is isolated to a particular part of the validation process. Expected answer: Mostly syntax errors in certain types of LookML files. Impact on approach: We'd focus on the specific validation rules for those file types.

• Thinking about user impact, I'm concerned about the scope. Is this affecting all users or a specific subset based on factors like project size or complexity?

Why it matters: Understanding the affected user base helps in prioritizing and targeting our investigation. Expected answer: Primarily affecting larger, more complex projects. Impact on approach: We'd examine how the validation process scales with project complexity.