AI Microservices Best Practices
Production-tested patterns for building resilient, scalable, and maintainable AI microservice architectures.
Resilience Patterns
- Circuit breakers: Prevent cascading failures when a model service is down. Return cached predictions or graceful degradation responses.
- Timeouts and deadlines: Set aggressive timeouts on model inference. A 30-second timeout prevents request pile-up during GPU issues.
- Retries with backoff: Retry transient failures (network errors, GPU OOM) with exponential backoff and jitter.
- Bulkheads: Isolate resource pools per model to prevent one model's load from starving others.
- Fallback models: Deploy smaller, faster fallback models that activate when primary models are unavailable.
Scaling Best Practices
| Strategy | When to Use | Implementation |
|---|---|---|
| Horizontal Pod Autoscaler | Variable traffic load | Scale on GPU utilization or queue depth |
| Vertical Pod Autoscaler | Memory-bound models | Right-size pod resources automatically |
| KEDA | Event-driven scaling | Scale based on Kafka lag or queue length |
| Cluster Autoscaler | Capacity planning | Add GPU nodes when pods are pending |
| Scale to zero | Low-traffic models | KNative or custom scale-to-zero with warm-up |
Testing AI Microservices
Contract Tests
Verify that service APIs match their contracts. Catch breaking changes before deployment using Pact or custom schema validators.
Model Integration Tests
Test that models produce expected outputs for known inputs. Include edge cases, adversarial inputs, and regression test cases.
Chaos Engineering
Inject failures (pod kills, network delays, GPU errors) to verify resilience patterns work. Use Chaos Monkey or LitmusChaos.
Load Testing
Simulate production traffic to find bottlenecks and breaking points. Use Locust or k6 with realistic request distributions.
CI/CD for AI Microservices
- Model CI: Automated model validation on every training run (accuracy thresholds, bias checks, latency benchmarks).
- Service CI: Standard code testing (linting, unit tests, integration tests) plus model loading and inference tests.
- Progressive delivery: Use canary deployments to gradually shift traffic to new model versions with automated rollback.
- Infrastructure as code: Define all Kubernetes manifests, Helm charts, and infrastructure in Git for reproducible deployments.
Frequently Asked Questions
There is no magic number, but a good rule of thumb is one service per independently deployable model or distinct business capability. If you find yourself coordinating deployments across many services frequently, you may have split too aggressively. Start with 3-5 services and split further only when you have a concrete need.
Not necessarily. Group models that share the same framework, hardware requirements, and deployment lifecycle into the same service. For example, three small text classification models can share a single Triton server. Split into separate services when models need different GPUs, scaling patterns, or update frequencies.
Create a dedicated model service that multiple consumers call. Use a model gateway pattern to route requests. Store models in a shared model registry (MLflow) and let each service pull the version it needs. Avoid duplicating model instances across services unless latency requirements demand it.
Premature decomposition. Teams often split into microservices before understanding their actual scaling and deployment needs. Start with a well-structured monolith, identify real pain points (different scaling needs, blocking deployments, different hardware), and then extract services strategically.
Lilly Tech Systems