How to change a node s availability

Question

I have 2 manager nodes and a couple of worker nodes in a swarm.I want to take the backup of the two manager nodes and hence need to go offline.Kindly specify how do I change the availability of these nodes and how do i maintain the swarm intact?

Answer 1

Hey @jenny,  You can do the following in case you want to change the manager nodes availability

$ docker node update --availability drain node-1

node-1

When a manager node becomes unavailable or if you want to take a manager offline for maintenance, You can promote a worker node to the manager role.Similarly, you can demote a manager node to the worker role.

Regardless of your reason to promote or demote a node, you must always maintain a quorum of manager nodes in the swarm.

• To promote a node or set of nodes, run docker node promote from a manager node:

$ docker node promote node-3 node-2

Node node-3 promoted to a manager in the swarm.
Node node-2 promoted to a manager in the swarm.

• To demote a node or set of nodes, run docker node demote from a manager node:

$ docker node demote node-3 node-2

Manager node-3 demoted in the swarm.
Manager node-2 demoted in the swarm.