Day 51 - Lambda Managed Instances Overview

Date: 2025-11-17 (Monday)
Status: “Planned”


Why Lambda Managed Instances

LMI keeps the Lambda dev model while letting you pick EC2 instance families and pricing (SP/RI), remove cold starts, and allow multi-concurrency per instance.

When to Use

  • Steady, high-traffic workloads needing predictable cost
  • Specialized compute/memory/network requirements
  • Desire to apply EC2 pricing instruments to Lambda functions

When to Stay on Default Lambda

  • Spiky/unpredictable traffic
  • Short, infrequent invocations where scale-to-zero is key

Benefits Snapshot

  • Same Lambda packaging/runtimes
  • No cold starts; predictable capacity
  • Cost control via EC2 constructs (savings plans, reserved instances)

Notes from re:Invent CNS382

  • Instances are AWS-managed: you can see but not SSH/edit
  • Lifecycle, patching, routing handled by Lambda
  • Multi-concurrency option changes price/perf profile