DCA Financial Management & Budgeting 3

Question 1

You need to pin a container to specific CPU cores to guarantee predictable performance for a critical billing service. Which flag should you use?

Accepted Answer

--cpuset-cpus=0,1

Answer

--cpuset-cpus pins a container to specific CPU core numbers, ensuring it always runs on those cores.

Question 2

A Docker Swarm service is over-provisioned with replicas during off-peak hours. Which command scales it down to 2 replicas to cut costs?

Accepted Answer

docker service scale myservice=2

Answer

docker service scale = is the direct command to adjust replica count in Docker Swarm.

Question 3

Which Docker log driver would you choose to minimize local disk consumption while sending logs to a centralized cost-tracked logging service?

Accepted Answer

awslogs

Answer

The awslogs driver ships logs directly to Amazon CloudWatch, eliminating local disk usage for log storage.

Question 4

A --memory-reservation flag is set lower than --memory for a container. What does this mean operationally?

Accepted Answer

The reservation is a soft limit Docker uses when the host is under memory pressure

Answer

Memory reservation is a soft guarantee; Docker tries to reclaim memory from the container down to this level when the host needs it.

Question 5

Which metric from 'docker stats' most directly reflects a container's I/O cost on cloud block storage billed per IOPS?

Accepted Answer

BLOCK I/O

Answer

BLOCK I/O reports bytes read/written to block devices, which maps directly to IOPS-billed cloud storage charges.

DCA - Docker Certified Associate Exam Practice Test