ECS with ALB integration in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the role of an Application Load Balancer (ALB) in ECS?

An ALB distributes incoming traffic evenly across ECS tasks, improving availability and scalability by routing requests to healthy containers.

intermediate

How does ECS register tasks with an ALB target group?

ECS automatically registers and deregisters tasks with the ALB target group based on task lifecycle, ensuring only healthy tasks receive traffic.

beginner

What is a listener in the context of ALB?

A listener checks for connection requests on a specified port and protocol, then forwards requests to target groups based on rules.

beginner

Why is health checking important in ECS with ALB integration?

Health checks let the ALB know which ECS tasks are healthy and can receive traffic, preventing requests from going to failed or unhealthy containers.

intermediate

What is the benefit of using dynamic port mapping in ECS with ALB?

Dynamic port mapping allows multiple tasks on the same instance to use different ports, letting the ALB route traffic correctly to each task without port conflicts.

What does an ALB use to decide where to send incoming traffic in ECS?

A Random selection of ECS instances

B Target groups with registered ECS tasks

C Only the first ECS task launched

D Static IP addresses

ALB forwards traffic to target groups that have ECS tasks registered and healthy.

Which ECS feature allows multiple tasks on one instance to use the ALB without port conflicts?

A Static port assignment

B Service discovery

C Task placement constraints

D Dynamic port mapping

Dynamic port mapping assigns different ports to tasks so ALB can route traffic properly.

What does an ALB listener do?

A Routes traffic based on rules and ports

B Launches ECS tasks

C Monitors ECS task health

D Manages ECS clusters

Listeners check for incoming requests and route them to target groups based on rules.

Why should ECS tasks be registered with an ALB target group?

A To receive traffic from the ALB

B To backup task data

C To store task logs

D To enable automatic scaling

Registration allows the ALB to send traffic to the ECS tasks.

What happens if an ECS task fails health checks from the ALB?

A It is restarted immediately by ALB

B It continues receiving traffic

C It is deregistered and stops receiving traffic

D Nothing changes

Unhealthy tasks are deregistered so ALB stops sending them traffic.

Explain how ECS integrates with an Application Load Balancer to manage incoming traffic.

Think about how ALB and ECS work together to route requests only to healthy containers.

Describe the role of listeners and target groups in ALB when used with ECS.

Focus on how ALB processes incoming requests and sends them to ECS tasks.