Why has AWS S3 data retrieval latency increased by 150%?

Introduction

The sudden 150% increase in AWS S3 data retrieval latency is a critical issue that demands immediate attention and a thorough root cause analysis. This significant performance degradation could have far-reaching consequences for our customers and our business. I'll approach this problem systematically, starting with clarifying questions to gather essential context, then moving through hypothesis generation, validation, and solution development.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking this might be a recent change. When exactly did you first notice this latency increase?

Why it matters: Helps pinpoint potential triggers and narrows the investigation timeframe. Expected answer: Within the last 24-48 hours. Impact on approach: Recent change suggests looking at recent deployments or configuration changes.

• Considering the scale, I'm wondering if this affects all S3 buckets or specific regions. Is the latency increase uniform across all AWS regions and bucket types?

Why it matters: Determines if it's a global issue or localized to specific infrastructure. Expected answer: Varies by region, with some more affected than others. Impact on approach: Focus on regional differences and potential infrastructure bottlenecks.

• Given the severity, I'm curious about user impact. Have we seen an increase in customer complaints or support tickets related to S3 performance?

Why it matters: Gauges real-world impact and urgency of the situation. Expected answer: Yes, significant increase in complaints, especially from high-volume users. Impact on approach: Prioritize high-impact customers and consider temporary workarounds.

• Thinking about recent changes, have there been any significant updates to S3 or related AWS services in the past week?

Why it matters: Identifies potential triggers for the latency increase. Expected answer: A minor update to S3's backend infrastructure was rolled out recently. Impact on approach: Investigate the update's impact and consider rollback options.