elasticsearch 启动报错：received plaintext http traffic on an https channel, closing connection Netty4HttpChannel。
现象，当启动Elasticsearch后，在浏览器输入地址 http://localhost:9200/
后，报错
received plaintext http traffic on an https channel, closing connection Netty4HttpChannel{localAddress=/127.0.0.1:9200, remoteAddress=/127.0.0.1:52077}
如图：
解决方案：
找到config/目录下面的elasticsearch.yml配置文件，把安全认证开关从原先的true都改成false，实现免密登录访问即可，修改这两处都为false后：
即可解决问题，再次打开http://localhost:9200/
就正常显示内容了：
