问题一：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
没有配置节点，至少需要配置discovery.seed_hosts/discovery.seed_providers/cluster.initial_master_nodes中的一个
discovery.seed_hosts: 集群主机列表
discovery.seed_providers: 基于配置文件配置集群主机列表
cluster.initial_master_nodes: 启动时初始化的参与选主的node
单节点在config/elasticsearch.yml增加：
discovery.seed_hosts: [“127.0.0.1”]
cluster.initial_master_nodes: [“node-1”]
问题二：
启动后报killed
默认需要堆内存2g,若不够可修改为128mb
config/jvm.options
增加
-Xms128m
-Xmx128m
