For a cluster with only one master-eligible node, what happens when you set the quorum setting to 2?

[elastico]

Elasticsearch docs state:

The discovery.zen.minimum_master_nodes sets the minimum number of master eligible nodes a node should "see" in order to win a master election.

So for a cluster with only one master-eligible node running as of course the master, what happens when you set the quorum setting to 2. Does changing that setting instantly takes the running master out of operation or does it mean that it can't self elect itself in the future since it needs to see another master-eligible node to be able to do that.

[fkelbert (Florian Kelbert)]

Hi @elastico ,

Two situations:

1. In case the cluster is already up and running, then this side of the cluster will not accept any writes as described here.
2. In case the cluster is not yet running, then the node will not start until a second master eligible node becomes available