Elasticsearch HDFS Repository Plugin 설치

[xodn0812 (taewooKim)]

HDFS 스냅샷을 위해 Elasticsearch HDFS Plugin을 설치하려고 하는데 잘 안되네요..

./bin/elasticsearch-plugin install repository-hdfs
이렇게 했는데 아래처럼 에러가 났습니다.

Exception in thread "main" java.net.UnknownHostException: artifacts.elastic.co
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:668)
    at sun.security.ssl.BaseSSLSocketImpl.connect(BaseSSLSocketImpl.java:173)
    at sun.net.NetworkClient.doConnect(NetworkClient.java:180)
    at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
    at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)
    at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:264)
    at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1105)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:999)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:153)
    at org.elasticsearch.plugins.InstallPluginCommand.urlExists(InstallPluginCommand.java:325)
    at org.elasticsearch.plugins.InstallPluginCommand.getElasticUrl(InstallPluginCommand.java:292)
    at org.elasticsearch.plugins.InstallPluginCommand.download(InstallPluginCommand.java:248)
    at org.elasticsearch.plugins.InstallPluginCommand.execute(InstallPluginCommand.java:223)
    at org.elasticsearch.plugins.InstallPluginCommand.execute(InstallPluginCommand.java:210)
    at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86)
    at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124)
    at org.elasticsearch.cli.MultiCommand.execute(MultiCommand.java:79)
    at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124)
    at org.elasticsearch.cli.Command.main(Command.java:90)
    at org.elasticsearch.plugins.PluginCli.main(PluginCli.java:48)

그래서
./bin/elasticsearch-plugin install ./repository-hdfs-6.3.2.zip
위처럼 했는데 또 안되네요..
Commands

list - Lists installed elasticsearch plugins
install - Install a plugin
remove - removes a plugin from Elasticsearch

Non-option arguments:
command              

Option         Description        
------         -----------        
-h, --help     show help          
-s, --silent   show minimal output
-v, --verbose  show verbose output
ERROR: Unknown plugin ./repository-hdfs-6.3.2.zip

공식 문서에서 시키는대로 했는데 왜이럴까요??

혹시 hadoop를 따로 설치하고 해줘야하나요??
하둡은 안 깔고 엘라스틱서치 6.3.2버전만 깐 상태입니다.