A company runs a critical microservice on Amazon ECS with an EC2 launch type. The service … — AWS Certified SysOps Administrator - Associate

A company runs a critical microservice on Amazon ECS with an EC2 launch type. The service has a desired task count of $10$ . Due to strict budget constraints, the underlying Auto Scaling group of EC2 instances is configured to not scale out, and there is no spare capacity in the cluster to run additional tasks. The SysOps Administrator needs to update the service to a new task definition. The deployment must guarantee that at least $5$ tasks are always running and healthy to handle baseline traffic. Which combination of minimum healthy percent and maximum percent settings will achieve this deployment goal?

Minimum healthy percent: $50\%$ , Maximum percent: $100\%$ Answer
B
Minimum healthy percent: $100\%$ , Maximum percent: $150\%$
C
Minimum healthy percent: $50\%$ , Maximum percent: $150\%$
D
Minimum healthy percent: $0\%$ , Maximum percent: $100\%$

Answer

Minimum healthy percent:

50\%

, Maximum percent:

100\%

The correct answer specifies a minimum healthy percent of

50\%

and a maximum percent of

100\%

. In Amazon ECS rolling updates, setting the minimum healthy percent to

50\%

allows ECS to stop up to

5

tasks (leaving

5

tasks, or

50\%

of the desired

10

, running and healthy). Setting the maximum percent to

100\%

ensures that the service does not attempt to launch more than

10

tasks at any point during the deployment. This prevents the need for additional EC2 host resources, ensuring the deployment succeeds within the current capacity constraints while meeting the requirement of keeping at least

5

tasks active.

Step-by-Step Solution

Determine the resource constraints of the ECS cluster.

The cluster is running at maximum capacity with no spare resources, and the underlying Auto Scaling group cannot scale out.

This constraints the maximum percent to

100\%

to ensure that the deployment does not attempt to provision additional tasks (which would require extra container instances) before stopping old ones.

Calculate the required minimum healthy percent to maintain service availability.

Since at least

5

out of

10

desired tasks must remain active, the minimum healthy percent must be

50\%

(

5 / 10 \times 100\%

This guarantees that the application retains enough active tasks during the rolling update to handle baseline traffic.

Combine the parameters and select the corresponding configuration.

Minimum healthy percent of

50\%

and maximum percent of

100\%

This combination successfully meets both the capacity constraint (no extra tasks run concurrently) and the availability constraint (at least half the tasks remain healthy).

Key Concept

Amazon ECS rolling update deployment settings (minimum healthy percent and maximum percent) control the capacity envelope during service updates.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic