Should Docker Swarm Master be separate physical node?

Question

I'm getting into Docker Swarm and here's the question I can't find answer for...

I have 3 physical hosts and I would like to create a cluster. Should I use separate (4th) physical host to run Swarm master and one more for KV store or I can run them in one of those 3 hosts and still be able to use all of them as Swarm nodes?

Thanks.

Answer 1

You can run the manager and the agent on the same node, and on such a small cluster it's probably ok, but also keep in mind the swarm manager does have extra responsibilities, and as such adds extra load on the box. The larger the cluster, the larger the load.

Answer 2

According to my experience a Swarm Manager cannot be a Swarm Agent. It may have changed since then though.

Maybe this answer could give you more details ( online version ).

Note that you can use the same node for the Swarm Manager and the KV master.