我通过kubernetes Pod在容器中启动了一个logstash服务，然后我自愿更改了配置以查看其行为。现在，服务的配置文件不是

output {
 elasticsearch {
   hosts => ["elasticsearch:9200"]
 }

但是

output {
 elasticsearch {
   hosts => ["elasticsearch1:9200"]
 }

然后，当我启动容器时，日志是：

[2023-01-13T14:26:49,474][INFO ][logstash.outputs.elasticsearch][main] Elasticsearch pool URLs updated {:changes=>{:removed=>[], :added=>[http://elasticsearch1:9200/]}}
[2023-01-13T14:26:50,076][WARN ][logstash.outputs.elasticsearch][main] Restored connection to ES instance {:url=>"http://elasticsearch1:9200/"}

因此引用elasticsearch1，然后突然引用elasticsearch

[2023-01-13T14:27:01,405][WARN ][logstash.licensechecker.licensereader] Attempted to resurrect connection to dead ES instance, but got an error {:url=>"http://elasticsearch:9200/", :exception=>LogStash::Outputs::ElasticSearch::HttpClient::Pool::HostUnreachableError, :message=>"Elasticsearch Unreachable: [http://elasticsearch:9200/][Manticore::ResolutionFailure] elasticsearch: Name or service not known"}

为甚么？