Docker Swarm

Question 1

Where we use Docker swarm ?

Answer 1

We use it to orchestrate multi-container apps that run on multiple hosts in contrast to docker compose which runs on one host.
It is composed of two things:
a) an enterprise secure cluster of hosts
b) an engine for orchestrate micro service apps

Question 2

What does the cluster provides?

Answer 2

encrypted distributed cluster store,
encrypted networks, mutual TLS, secure cluster join tokens, and a PKI that makes
managing and rotating certificates a breeze

Question 3

From clustering view point, what is a swarm?

Answer 3

Swarm is a cluster of physical docker hosts.

Question 4

On swarm , what is etcd?

Answer 4

etcd is a distributed database on all nodes which preserves the state of the swarm.

Question 5

How the nodes (meaning categories ) are divided?

Answer 5

Nodes are configured as managers or workers. Managers look after the control plane
of the cluster, meaning things like the state of the cluster and dispatching tasks to
workers. Workers accept tasks from managers and execute them.