AWS Certified Cloud Practitioner (CLF-C02)Cloud Technology and ServicesMedium
A company is auditing its AWS environment and discovers that some EC2 instances are running in an Availability Zone that is experiencing higher latency to its users compared to other Availability Zones in the same Region. They want to shift traffic away from this high-latency AZ and distribute it more efficiently to other healthy AZs. Which AWS service can help them achieve this dynamic traffic management?
- AAmazon CloudWatch
- BAmazon Route 53
- CAWS Global Accelerator
- DElastic Load Balancing (ELB)
Show answer & explanationAnswer & explanation
Correct answer: D. Elastic Load Balancing (ELB)
Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets, such as EC2 instances, in multiple Availability Zones. If an Availability Zone or instance within an AZ becomes unhealthy or performs poorly (e.g., high latency), ELB can detect this and automatically route traffic away from it to healthy targets, improving overall application availability and performance.
Why the other options are wrong
- A. Amazon CloudWatch is a monitoring service that collects metrics and logs, but it does not actively re-route traffic based on performance issues.
- B. Amazon Route 53 is a DNS service that can route traffic based on various policies, but ELB is specifically designed for dynamic health checks and traffic distribution across instances and AZs within a Region.
- C. AWS Global Accelerator improves availability and performance by directing traffic to optimal AWS Regions globally, but ELB handles traffic distribution within a Region across AZs based on health.
Elastic Load Balancing (ELB)
Automatically distributes incoming application traffic across multiple targets, such as EC2 instances, containers, IP addresses, and Lambda functions, in one or more Availability Zones.
- Enhances availability and fault tolerance.
- Performs health checks on registered targets.
- Supports different load balancer types: Application Load Balancer (ALB), Network Load Balancer (NLB), Gateway Load Balancer (GLB), Classic Load Balancer (CLB).
Memory trick: ELB: Evenly Load Balance within your Region.