Hi using ES 1.6.0 and the latest AWS dicovery plugin 2.6.0
There is no errors reported in logs, but the nodes don't see each other.
I setup up 2 master nodes as follows...
bootstrap.mlockall: true
cluster.name: my-cluster
# And 02 for the second master
node.name: "ES MASTER 01"
node.data: false
node.master: true
plugin.mandatory: "cloud-aws"
cloud.aws.access_key: "AKI...Z7Q"
cloud.aws.secret_key: "gKW...nAO"
cloud.aws.region: "us-east"
discovery.zen.minimum_master_nodes: 1
discovery.type: "ec2"
discovery.ec2.groups: "Elastic Search"
discovery.ec2.ping_timeout: "30s"
discovery.ec2.availability_zones: "us-east-1a"
discovery.zen.ping.multicast.enabled: false
Here are the logs...
[2015-07-13 15:02:19,346][INFO ][node ] [ES MASTER 01] version[1.6.0], pid[2532], build[cdd3ac4/2015-06-09T13:36:34Z]
[2015-07-13 15:02:19,346][INFO ][node ] [ES MASTER 01] initializing ...
[2015-07-13 15:02:19,378][INFO ][plugins ] [ES MASTER 01] loaded [cloud-aws], sites []
[2015-07-13 15:02:19,440][INFO ][env ] [ES MASTER 01] using [1] data paths, mounts [[(C:)]], net usable_space [6.8gb], net total_space [29.9gb], types [NTFS]
[2015-07-13 15:02:26,461][INFO ][node ] [ES MASTER 01] initialized
[2015-07-13 15:02:26,461][INFO ][node ] [ES MASTER 01] starting ...
[2015-07-13 15:02:26,851][INFO ][transport ] [ES MASTER 01] bound_address {inet[/0:0:0:0:0:0:0:0:9300]}, publish_address {inet[/172.30.0.123:9300]}
[2015-07-13 15:02:26,866][INFO ][discovery ] [ES MASTER 01] my-cluster/SwhSDhiDQzq4pM8jkhIuzw
[2015-07-13 15:02:56,884][WARN ][discovery ] [ES MASTER 01] waited for 30s and no initial state was set by the discovery
[2015-07-13 15:02:56,962][INFO ][http ] [ES MASTER 01] bound_address {inet[/0:0:0:0:0:0:0:0:9200]}, publish_address {inet[/172.30.0.123:9200]}
[2015-07-13 15:02:56,962][INFO ][node ] [ES MASTER 01] started
[2015-07-13 15:03:13,455][INFO ][cluster.service ] [ES MASTER 01] new_master [ES MASTER 01][SwhSDhiDQzq4pM8jkhIuzw][WIN-3Q4EH3B8H1O][inet[/172.30.0.123:9300]]{data=false, master=true}, reason: zen-disco-join (elected_as_master)
[2015-07-13 15:03:13,517][INFO ][gateway ] [ES MASTER 01] recovered [0] indices into cluster_state