Module 13
Patterns for safe deployments and operational excellence: blue-green, canary, feature flags, immutable infrastructure, and external configuration.
Run two identical production environments: instant rollback, zero-downtime deployment, database migration challenges, and traffic switching strategies.
Gradually roll out changes to a subset of users: traffic splitting, automated rollback triggers, metrics-based promotion, and A/B testing integration.
Decouple deployment from release: flag types (release, experiment, ops, permission), flag lifecycle management, and technical debt considerations.
Incrementally replace instances with new versions: max surge, max unavailable, health check integration, and handling backward-incompatible changes.
Never modify running servers: build new images, deploy, destroy old ones. Golden images, container images, and infrastructure-as-code integration.
Separate configuration from code: centralized config services (Consul, etcd, AWS Parameter Store), hot reloading, and secrets management.
Attach observability sidecars for logging, metrics, and distributed tracing: Envoy, Fluentd, OpenTelemetry collector, and service mesh integration.