The changes related to Discovery are as follows:
- The cluster.initial_master_nodes setting must be set before cluster bootstrapping is performed.
- If half or more of the master-eligible nodes are going to remove from a cluster, those affected nodes must be excluded from the voting configuration using the _cluster/voting_config_exclusions API.
- At least one of the following settings must be specified in the elastiscearch.yml configuration file.
- discovery.seed_hosts
- discovery.seed_providers
- cluster.initial_master_nodes
- discovery.zen.ping.unicast.hosts
- discovery.zen.hosts_provider
- Use the setting name cluster.no_master_block instead of discovery.zen.no_master_block, which is deprecated.
- The default timeout for heartbeat fault ...