You are a PM at Google Cloud and you realized that for a set of users, VMs (Virtual Machines) have been underutilized or not utilized at all. How do you identify the root cause? How do you solve the issue and ensure that it won't happen again?

Introduction

Underutilized or unused Virtual Machines (VMs) in Google Cloud represent a significant challenge, impacting resource efficiency and potentially increasing costs for our users. To address this issue, I'll employ a systematic approach to identify the root cause, develop solutions, and implement preventive measures.

Step 1

Clarifying Questions (3 minutes)

• What specific metrics are we using to define "underutilized" VMs?

• Why: Establishes a clear baseline for analysis
• Hypothetical answer: CPU usage below 10% for 80% of uptime
• Impact: Helps focus on relevant data points

• Which user segments are most affected by this issue?

• Why: Identifies patterns and potential user-specific factors
• Hypothetical answer: Primarily affecting enterprise customers in the finance sector
• Impact: Guides targeted solutions and communication strategies

• Have there been any recent changes to the VM provisioning or management systems?

• Why: Pinpoints potential technical triggers
• Hypothetical answer: A new auto-scaling feature was implemented last month
• Impact: Narrows down investigation to recent system changes

• What's the time frame for this observed underutilization?

• Why: Distinguishes between short-term fluctuations and persistent issues
• Hypothetical answer: Trend observed over the past 3 months
• Impact: Helps determine if it's a new issue or a long-standing problem

• Has there been any change in how we measure or define VM utilization?

• Why: Ensures consistency in metrics and reporting
• Hypothetical answer: No recent changes to utilization metrics
• Impact: Confirms the issue is not due to measurement discrepancies