Managers and workers

We have discussed swarm managers a little in the previous sections, but let's take a closer look at what swarm managers do. The swarm managers do exactly what you would expect. They manage and maintain the state of the swarm cluster. They schedule swarm services, which we will talk about in Swarm services section of this chapter, but for now, think of swarm services as running containers. Manager nodes also serve up the API endpoints of the cluster, allowing for programmatic access via REST. Managers also direct traffic to the running services so that any container can be reached through any manager node without having to know which node is actually running the containers. As part of maintaining the state of the cluster, the managers will deal with the loss of nodes in the system, electing a new leader node in the event that the manager lost was the leader...