Service Mesh

When to Use

• Mature Microservices: You have 20+ services and managing retries, timeouts, and auth in each language is becoming a nightmare.
• Zero Trust Security: You need mTLS (Mutual TLS) between all services.
• Observability: You need uniform metrics (Gold signals) and tracing across a polyglot stack.

Core Concepts

Sidecar Proxy

Control Plane

Data Plane

Features

• Traffic Management: Canary deployments (1% traffic to v2), Circuit Breaking, Retries.
• Security: mTLS rotation, Authorization policies.
• Observability: Automatic metrics (latency, success rate) without code changes.

Best Practices

• Assess if the Complexity is worth it. For small clusters, it's overkill.
• Use simpler alternatives (Linkerd) if Istio is too heavy.
• Start with Observability features before enabling strict enforcement/mTLS.

• Don't use a Service Mesh to fix bad application code.
• Don't ignore the resource overhead (CPU/RAM) of sidecars at scale.

References

• Istio
• Linkerd
• The Service Mesh Pattern