Why did AWS EC2 instance launch time increase to 4 minutes?

Introduction

The sudden increase in AWS EC2 instance launch time to 4 minutes is a critical issue that demands immediate attention. This performance degradation could significantly impact user experience, operational efficiency, and potentially lead to customer churn. 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)

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

Why it matters: Helps pinpoint potential triggers and narrows the investigation timeframe. Expected answer: Within the last week or two. Impact on approach: Recent changes would be prioritized in the investigation.

• Considering the complexity of EC2, I'm wondering if this affects all instance types. Is the 4-minute launch time consistent across all EC2 instance types and sizes?

Why it matters: Identifies if the issue is systemic or specific to certain configurations. Expected answer: Varies by instance type, with some more affected than others. Impact on approach: Would focus on commonalities among affected instances.

• Given the potential impact, I'm curious about the scale. What percentage of EC2 launches are experiencing this delay?

Why it matters: Determines the severity and scope of the problem. Expected answer: A significant portion, around 70-80% of launches. Impact on approach: High percentage would indicate a widespread issue requiring urgent attention.

• Thinking about recent updates, have there been any significant changes to the EC2 service, underlying infrastructure, or related AWS services in the past month?

Why it matters: Identifies potential triggers for the performance degradation. Expected answer: Yes, a recent update to the EC2 control plane. Impact on approach: Would focus investigation on the impact of this update.

• Considering user feedback, have you noticed any patterns in customer complaints or support tickets related to this issue?

Why it matters: Provides insights into user impact and potential causes from the customer perspective. Expected answer: Increased tickets mentioning slow launches, especially for certain use cases. Impact on approach: Would incorporate user feedback into hypothesis formation and prioritization.