一：
javaApi通过tcp9300调用es集群，遇到的问题。
Exception in thread "main" NoNodeAvailableException[None of the configured nodes are available: [{#transport#-1}{xT4bF9ImTUiamYI9VJxKUA}{39.96.53.24}{39.96.53.24:9300}]] at org.elasticsearch.client.transport.TransportClientNodesService.ensureNodesAreAvailable(TransportClientNodesService.java:351) at org.elasticsearch.client.transport.TransportClientNodesService.execute(TransportClientNodesService.java:249) at org.elasticsearch.client.transport.TransportProxyClient.execute(TransportProxyClient.java:60) at org.elasticsearch.client.transport.TransportClient.doExecute(TransportClient.java:388) at org.elasticsearch.client.support.AbstractClient.execute(AbstractClient.java:403) at org.elasticsearch.client.support.AbstractClient.execute(AbstractClient.java:391) at org.elasticsearch.action.ActionRequestBuilder.execute(ActionRequestBuilder.java:46) at org.elasticsearch.action.ActionRequestBuilder.get(ActionRequestBuilder.java:53) at cn.example.DocumentDemo.main(DocumentDemo.java:121)
一步步debug发现是，发现集群时产生的报错。暂时先注释掉（ .put("client.transport.sniff", true) ）。
Settings esSettings = Settings.builder() .put("cluster.name", clusterName) // .put("client.transport.sniff", true)// 自动嗅探整个集群状态，把其他ES节点ip添加到客户端。 .build();
