DCA Docker Swarm & Orchestration 2

Question 1

What is the minimum number of manager nodes required so that a Docker Swarm can tolerate the failure of one manager?

Accepted Answer

3

Answer

Three managers are the minimum for single-node fault tolerance because Raft requires a majority quorum (2 of 3) to remain operational.

Question 2

What does the Raft consensus algorithm provide in a Docker Swarm cluster?

Accepted Answer

Consistent distributed state management across manager nodes

Answer

Raft ensures all manager nodes agree on the cluster state and can elect a new leader if the current one fails, providing a consistent and fault-tolerant control plane.

Question 3

Which command sets the availability of a Swarm node named 'node1' to 'drain'?

Accepted Answer

docker node update --availability drain node1

Answer

`docker node update --availability drain node1` prevents new tasks from being scheduled on the node and reschedules existing tasks elsewhere.

Question 4

What is a Docker Stack in the context of Swarm mode?

Accepted Answer

A group of interrelated services deployed together using a Compose-format file

Answer

A Docker Stack bundles multiple services defined in a Compose file and deploys them as a unit to a Swarm, enabling multi-service orchestration.

Question 5

Which command deploys a stack named 'myapp' to a Swarm using 'docker-compose.yml'?

Accepted Answer

docker stack deploy -c docker-compose.yml myapp

Answer

`docker stack deploy -c docker-compose.yml myapp` reads the Compose file and deploys the defined services as a stack to the active Swarm.

DCA - Docker Certified Associate Exam Practice Test

DCA - Docker Certified Associate Exam Practice Test

DCA Docker Swarm & Orchestration 2