AWS S3 basics
S3 is durable object storage used for files, backups, logs, static assets, and data lake style workloads.
- Object storage not block storage
- Highly durable
- Great for static files and archives
AWS S3 basics
DevOps cards
25 cards
Blue-green deployment vs rolling deployment
Rolling replaces instances gradually, while blue-green keeps old and new environments side by side and switches traffic in one move.
- Rolling is resource-efficient
- Blue-green is cleaner for fast rollback
- Trade cost for safety
Blue-green deployment vs rolling deployment
ConfigMap vs Secret in Kubernetes
ConfigMaps store non-sensitive config, while Secrets are meant for sensitive values such as tokens or passwords.
- Both can be mounted or injected
- Secrets are not plain config by intent
- Still require cluster security controls
ConfigMap vs Secret in Kubernetes
Docker basics
Docker packages an app with its runtime and dependencies into a portable container image.
- Image is a blueprint
- Container is a running instance
- Improves environment consistency
Docker basics
How do rolling updates work in Kubernetes?
Kubernetes Deployments roll out new replicas gradually while keeping part of the old replica set available.
- Controlled by maxUnavailable and maxSurge
- Supports rollback
- Readiness affects safe rollout
How do rolling updates work in Kubernetes?
Kubernetes basics
Kubernetes orchestrates containers across machines and handles scheduling, scaling, and service discovery.
- Pod is smallest deployable unit
- Deployment manages replicas
- Service provides stable access
Kubernetes basics
Liveness vs readiness probes in Kubernetes
Liveness decides whether a container should be restarted, while readiness decides whether it should receive traffic.
- Liveness for stuck processes
- Readiness for traffic safety
- Misconfigured probes can cause outages
Liveness vs readiness probes in Kubernetes
Load balancer types in AWS
AWS offers load balancers for different layers, with ALB for HTTP/S, NLB for very high-performance TCP/UDP, and GWLB for network appliances.
- ALB is app-layer aware
- NLB is lower-level and fast
- Choose based on protocol and routing needs
Load balancer types in AWS
Logging and monitoring basics
Logs explain events, metrics show trends, and alerts tell you when user-impacting thresholds break.
- Use structured logs
- Track golden signals
- Alert on symptoms users feel
Logging and monitoring basics
Node affinity and taints in Kubernetes
Affinity attracts workloads to certain nodes; taints repel workloads unless they have matching tolerations.
- Affinity is placement preference or rule
- Taints push workloads away
- Useful for GPU, critical, or isolated nodes
Node affinity and taints in Kubernetes