Kibana连接不上ElasticSearch，报错： Request Timeout after 30000ms，如何解决？

Question

环境：阿里云ECS CentOS7
e:7.6.2 k:7.6.2
详细报错信息如下：
`Apr 29 11:42:28 kibana[28283]: Could not create APM Agent configuration: Request Timeout after 30000ms
Apr 29 11:42:28 kibana[28283]: {"type":"log","@timestamp":"2020-04-29T03:42:28Z","tags":["warning","savedobjects-service"],"pid":28283,"message":"Unable to connect to Elasticsearch. Error: Request Timeout after 30000ms"}
`