David - I have pasted my yml file here, kindly correct me where i did mistake.
cluster.name: graylog
node.name: "Node01"
index.number_of_shards: 5
index.number_of_replicas: 1
path.data: /opt/data1/ESData/Index
path.logs: /opt/data1/ESData/logs
bootstrap.memory_lock: true
discovery.zen.minimum_master_nodes: 1
discovery.zen.ping.timeout: 3s
discovery.seed_hosts: ["10.46.XX.XX", "10.46.XX.XX"]
cluster.initial_master_nodes: ["Node01", "Node02"]
discovery.zen.ping.multicast.enabled: false
threadpool.bulk.queue_size: 1000
index.routing.allocation.disable_allocation: false