When running workloads in the cloud, cost optimization is always a priority. Google Compute Engine (GCE) offers Spot VMs, which are temporary instances available at 60–91% lower cost compared to standard VMs.
But why so cheap? Let’s break it down. 👇
🔹 What are Spot VM Instances?
Spot VMs are created from excess Compute Engine capacity.
They are cost-efficient but come with a trade-off → they can be preempted (stopped or deleted) anytime by Google if resources are needed elsewhere.
Before termination, your VM receives a 30-second warning to save important work.
🔹 Why are Spot VMs Cheaper?
Spot VMs are not guaranteed to keep running.
They may be stopped or deleted anytime.
Memory is not preserved when a Spot VM stops or is deleted.
You can choose between:
- Stop VM (Default) → Can restart later, but memory is not preserved
- Delete VM → Permanently deleted
This uncertainty makes them available at massive discounts (60–91%) compared to regular VMs.
🔹 Fault-Tolerance is the Key
To use Spot VMs effectively, your workloads must be fault-tolerant → designed to keep going even if a VM is terminated.
Think: Stateless applications, batch jobs, or distributed systems where losing a node doesn’t affect the overall system.
🔹 Limitations of Spot VMs
⚠️ Before choosing Spot VMs, keep these in mind:
Can be preempted at any time by Google.
❌ No Live Migration support (VM will just terminate).
❌ No Automatic Restart option during maintenance.
❌ No SLA (Service Level Agreement).
❌ Not always available (capacity is finite).
❌ Not covered under Free Tier credits.
🔹 Where to Use Spot VMs?
Spot VMs are perfect for cost-sensitive workloads where interruptions are acceptable.
✅ Regular Workloads
- High Performance Computing (HPC)
- Big Data & Analytics
- CI/CD pipelines
- Batch Processing
✅ Container Workloads
- Use Spot VMs to create Google Kubernetes Engine (GKE) node pools → saves costs in containerized environments.
Temporary VM Instances
📝 Final Thoughts
Spot VMs are a powerful cost-saving option for workloads that can tolerate interruptions. They’re not suited for mission-critical apps that require guaranteed uptime, but for the right use cases (like analytics, CI/CD, or batch jobs), they can drastically reduce cloud costs.
💡 Pro Tip: Always combine Spot VMs with a fault-tolerant architecture (e.g., auto-scaling, checkpointing, retries) to make the most out of them.