Hi @Christian_Dahlqvist.
You are correct But i tried but no luck.
please check below logfile for both HOST:-
HOST IP(This is not working)
[2019-08-05T22:20:09,832][INFO ][o.e.p.PluginsService ] [slave1] loaded module [x-pack-watcher]
[2019-08-05T22:20:09,832][INFO ][o.e.p.PluginsService ] [slave1] no plugins loaded
[2019-08-05T22:20:12,811][INFO ][o.e.x.s.a.s.FileRolesStore] [slave1] parsed [0] roles from file [/etc/elasticsearch/roles.yml]
[2019-08-05T22:20:13,385][INFO ][o.e.x.m.p.l.CppLogMessageHandler] [slave1] [controller/5989] [Main.cc@110] controller (64 bit): Version 7.3.0 (Build ff2f774f78ce63) Copyright (c) 2019 Elasticsearch BV
[2019-08-05T22:20:13,744][DEBUG][o.e.a.ActionModule ] [slave1] Using REST wrapper from plugin org.elasticsearch.xpack.security.Security
[2019-08-05T22:20:14,180][INFO ][o.e.d.DiscoveryModule ] [slave1] using discovery type [zen] and seed hosts providers [settings]
[2019-08-05T22:20:14,836][INFO ][o.e.n.Node ] [slave1] initialized
[2019-08-05T22:20:14,837][INFO ][o.e.n.Node ] [slave1] starting ...
[2019-08-05T22:20:14,990][INFO ][o.e.t.TransportService ] [slave1] publish_address {192.168.1.54:9300}, bound_addresses {192.168.1.54:9300}
[2019-08-05T22:20:14,997][INFO ][o.e.b.BootstrapChecks ] [slave1] bound or publishing to a non-loopback address, enforcing bootstrap checks
[2019-08-05T22:20:15,017][ERROR][o.e.b.Bootstrap ] [slave1] node validation exception
[3] bootstrap checks failed
[1]: max number of threads [1024] for user [elasticsearch] is too low, increase to at least [4096]
[2]: system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
[3]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured
[2019-08-05T22:20:15,021][INFO ][o.e.n.Node ] [slave1] stopping ...
[2019-08-05T22:20:15,048][INFO ][o.e.n.Node ] [slave1] stopped
[2019-08-05T22:20:15,048][INFO ][o.e.n.Node ] [slave1] closing ...
[2019-08-05T22:20:15,057][INFO ][o.e.n.Node ] [slave1] closed
[2019-08-05T22:20:15,059][INFO ][o.e.x.m.p.NativeController] [slave1] Native controller process has stopped - no new native processes can be started
LOCALHOST(This is working)
[2019-08-06T15:10:07,711][INFO ][o.e.p.PluginsService ] [slave1] no plugins loaded
[2019-08-06T15:10:10,751][INFO ][o.e.x.s.a.s.FileRolesStore] [slave1] parsed [0] roles from file [/etc/elasticsearch/roles.yml]
[2019-08-06T15:10:11,286][INFO ][o.e.x.m.p.l.CppLogMessageHandler] [slave1] [controller/11544] [Main.cc@110] controller (64 bit): Version 7.3.0 (Build ff2f774f78ce63) Copyright (c) 2019 Elasticsearch BV
[2019-08-06T15:10:11,657][DEBUG][o.e.a.ActionModule ] [slave1] Using REST wrapper from plugin org.elasticsearch.xpack.security.Security
[2019-08-06T15:10:11,982][INFO ][o.e.d.DiscoveryModule ] [slave1] using discovery type [zen] and seed hosts providers [settings]
[2019-08-06T15:10:12,675][INFO ][o.e.n.Node ] [slave1] initialized
[2019-08-06T15:10:12,675][INFO ][o.e.n.Node ] [slave1] starting ...
[2019-08-06T15:10:12,781][INFO ][o.e.t.TransportService ] [slave1] publish_address {127.0.0.1:9300}, bound_addresses {127.0.0.1:9300}
[2019-08-06T15:10:12,805][WARN ][o.e.b.BootstrapChecks ] [slave1] max number of threads [1024] for user [elasticsearch] is too low, increase to at least [4096]
[2019-08-06T15:10:12,805][WARN ][o.e.b.BootstrapChecks ] [slave1] system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
[2019-08-06T15:10:12,806][WARN ][o.e.b.BootstrapChecks ] [slave1] the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured
[2019-08-06T15:10:12,810][INFO ][o.e.c.c.Coordinator ] [slave1] cluster UUID [5z2yU2NwRcmxNTGBtaS_vA]
[2019-08-06T15:10:12,820][INFO ][o.e.c.c.ClusterBootstrapService] [slave1] no discovery configuration found, will perform best-effort cluster bootstrapping after [3s] unless existing master is discovered
[2019-08-06T15:10:13,019][INFO ][o.e.c.s.MasterService ] [slave1] elected-as-master ([1] nodes joined)[{slave1}{qaizxPLtTqCh6LsWzxPLWg}{yxcbxHIvQpOmvd73wN1Kvw}{localhost}{127.0.0.1:9300}{dim}{ml.machine_memory=16640958464, xpack.installed=true, ml.max_open_jobs=20} elect leader, _BECOME_MASTER_TASK_, _FINISH_ELECTION_], term: 15, version: 69, reason: master node changed {previous [], current [{slave1}{qaizxPLtTqCh6LsWzxPLWg}{yxcbxHIvQpOmvd73wN1Kvw}{localhost}{127.0.0.1:9300}{dim}{ml.machine_memory=16640958464, xpack.installed=true, ml.max_open_jobs=20}]}
[2019-08-06T15:10:13,238][INFO ][o.e.c.s.ClusterApplierService] [slave1] master node changed {previous [], current [{slave1}{qaizxPLtTqCh6LsWzxPLWg}{yxcbxHIvQpOmvd73wN1Kvw}{localhost}{127.0.0.1:9300}{dim}{ml.machine_memory=16640958464, xpack.installed=true, ml.max_open_jobs=20}]}, term: 15, version: 69, reason: Publication{term=15, version=69}
[2019-08-06T15:10:13,283][INFO ][o.e.h.AbstractHttpServerTransport] [slave1] publish_address {127.0.0.1:9200}, bound_addresses {127.0.0.1:9200}
[2019-08-06T15:10:13,284][INFO ][o.e.n.Node ] [slave1] started
[2019-08-06T15:10:13,507][INFO ][o.e.l.LicenseService ] [slave1] license [5ff6a681-c8b7-4c6a-8b32-5f2c1e78b9fa] mode [basic] - valid
[2019-08-06T15:10:13,508][INFO ][o.e.x.s.s.SecurityStatusChangeListener] [slave1] Active license is now [BASIC]; Security is disabled
[2019-08-06T15:10:13,515][INFO ][o.e.g.GatewayService ] [slave1] recovered [1] indices into cluster_state
[2019-08-06T15:10:14,124][INFO ][o.e.c.r.a.AllocationService] [slave1] Cluster health status changed from [RED] to [YELLOW] (reason: [shards started [[mybucket][0]] ...]).