Scalability, Elasticity and Reliability
Cloud Concepts questions test horizontal scaling, vertical scaling, elasticity, load balancing, fault tolerance, availability, and managed resilience.
How to study for AWS Cloud Practitioner
Treat each question as a service-selection or responsibility decision: identify the business need, AWS responsibility, customer configuration, and best-fit service.
Core concepts
Concept 1
Scalability is the ability to increase or decrease resources to meet demand.
Exam cue: Use horizontal scaling and load balancing for growing request volume.
Concept 2
Elasticity is dynamic capacity adjustment, often automatic, to align resources with current workload.
Exam cue: Use elasticity for variable or unpredictable demand.
Concept 3
Reliability improves through redundancy, health checks, multi-AZ design, backups, managed services, and recovery planning.
Exam cue: Use multi-AZ and backup design for reliability requirements.
Risk pitfalls and guardrails
Confusing elasticity with a one-time capacity increase.
Guardrail: Avoid answers that ignore customer configuration, choose unmanaged services when managed services fit, or use billing reports when proactive alerts are required.
Relying on one instance when high availability is required.
Guardrail: Avoid answers that ignore customer configuration, choose unmanaged services when managed services fit, or use billing reports when proactive alerts are required.
Choosing vertical scaling when distributed scale is the better fit.
Guardrail: Avoid answers that ignore customer configuration, choose unmanaged services when managed services fit, or use billing reports when proactive alerts are required.
Memory anchors
Scalability
Scalability is the ability to handle more or less demand by changing capacity.
Elasticity
Elasticity automatically or quickly adjusts capacity to current demand.
Horizontal Scaling
Horizontal scaling adds more resource instances to handle demand.
Vertical Scaling
Vertical scaling increases the size or capability of one resource.
Load Balancing
Load balancing distributes traffic across multiple targets.
Fault Tolerance
Fault tolerance lets a workload continue operating when a component fails.
Health Check
A health check verifies whether a target should receive traffic.
Multi-AZ
Multi-AZ design uses multiple Availability Zones to reduce single-location failure risk.
Backup
A backup is a copy retained for recovery after loss, corruption, or deletion.
Managed Service
A managed service shifts operational work to AWS while the customer configures and uses the service.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
A web tier adds more EC2 instances behind a load balancer as request volume grows. What type of scaling is this?
A database server is changed from an instance with 8 GiB of memory to one with 32 GiB of memory. Which scaling approach is being used?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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