Why has Temporal's workflow execution success rate dropped by 15% over the past week?

Introduction

The sudden 15% drop in Temporal's workflow execution success rate over the past week is a critical issue that demands immediate attention. This decline could significantly impact user satisfaction, system reliability, and overall product performance. 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 could be related to a recent deployment. Have there been any significant changes or updates to the Temporal system in the past 1-2 weeks?

Why it matters: Recent changes often correlate with performance issues. Expected answer: Yes, there was a major update last week. Impact on approach: If confirmed, I'd focus on the changes made in that update.

• Considering the scale of the drop, I'm wondering about the affected user base. Is this decline uniform across all users, or are certain segments more impacted?

Why it matters: Helps identify if it's a global issue or specific to certain use cases. Expected answer: The impact varies across user segments. Impact on approach: I'd prioritize investigating the most affected segments first.

• Given the nature of workflow executions, I'm curious about error patterns. Has there been an increase in specific types of errors or failures?

Why it matters: Error patterns can point to specific system components or user behaviors. Expected answer: Yes, there's been an increase in timeout errors. Impact on approach: I'd focus on performance bottlenecks and resource allocation.

• Thinking about external factors, I'm considering potential changes in usage patterns. Has there been any significant increase in workflow complexity or volume recently?

Why it matters: Changes in usage can strain system resources. Expected answer: Workflow volume has increased by 20% in the past month. Impact on approach: I'd investigate scalability issues and resource management.