Why has Dremio's Arctic data lake acceleration seen a 20% drop in query performance over the last month?

Introduction

Dremio's Arctic data lake acceleration experiencing a 20% drop in query performance over the last month is a critical issue that demands immediate attention. This performance degradation directly impacts user experience and could potentially erode trust in Dremio's core value proposition. I'll approach this problem systematically, focusing on identifying the root cause, validating hypotheses, and developing both short-term fixes and long-term solutions.

Step 1

Clarifying Questions (3 minutes)

• Given the sudden drop, I'm thinking there might have been a recent system change. Has there been any significant update to Arctic's architecture or codebase in the past 1-2 months?

Why it matters: Recent changes often correlate with performance issues. Expected answer: Yes, there was a major update to the query optimizer. Impact on approach: If confirmed, I'd focus on the new optimizer's implementation and configuration.

• Considering user behavior, I'm curious about query patterns. Have we seen any shift in the types or complexity of queries being run by users recently?

Why it matters: Changes in query patterns could explain performance drops. Expected answer: There's been an increase in complex join operations. Impact on approach: I'd investigate if our system is optimized for these new query patterns.

• Looking at data volume, I'm wondering if there's been a significant increase in the amount of data being processed. Has the data lake size grown substantially in the last month?

Why it matters: Data volume directly impacts query performance. Expected answer: Yes, we've seen a 30% increase in data volume. Impact on approach: I'd focus on scaling solutions and optimizing for larger datasets.

• Thinking about infrastructure, I'm curious about any changes in our cloud resources. Have we made any modifications to our cloud configuration or provider?

Why it matters: Cloud resource changes can significantly impact performance. Expected answer: No changes to cloud configuration. Impact on approach: I'd shift focus to software and data-related issues rather than infrastructure.