Difference between worker and manager?


In Swarm mode, we have two main node types, worker and manager.
But the documentation says that a manager is like a worker node and will run a service also.
So what is the difference between a worker and a manager?
In which case should I use worker node if a manager node can do both, run containers and manage the swarm cluster?


While a manager node can also run service containers (unless you define a different scheduling rule), the thing that manager nodes do that worker nodes can’t is to coordinate the cluster quorum - it’s the machine telling the others (and itself) what to do.

hi, I’m new to docker and this was important question for me… let me followup
if master node is cluster “admin” and quorum manager, than an effective cluster has more than 1 master in case of server failure, is that safe to assume?
an effective cluster in most linux product is a 3 way “masters” ? is it the case in docker ?

essentially, if you have a 2+ physical docker server running the demon, than you will add a 3rd, 4th …n as a worker… but if you have a 2 or 3 nodes probably they will all be master?
is that the case?