一、Java環境

Elasticsearch是用Java語言編寫的，所以首先確保機器上已經安裝了Java環境。官方文件指出，至少需要Java 7，本文中使用java8。

二、下載Elasticsearch

在官網https://www.elastic.co/downloads/elasticsearch下載安裝包，本文下載的是elasticsearch-6.4.3.tar.gz,將下載的安裝包上傳至伺服器上。

三、解壓

tar zxvf elasticsearch-6.4.3.tar.gz -C /usr/local

四、執行

(1) 定位至安裝目錄：

cd /usr/local/elasticsearch-6.4.3/
 

(2) 執行

./bin/elasticsearch

五、錯誤解決

• java記憶體空間不足或檔案許可權不足：

Exception in thread "main" java.nio.file.AccessDeniedException: /usr/local/elasticsearch-6.4.3/config/jvm.options
        at sun.nio.fs.UnixException.translateToIOException(UnixException.java:84)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
        at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214)
        at java.nio.file.Files.newByteChannel(Files.java:361)
        at java.nio.file.Files.newByteChannel(Files.java:407)
        at java.nio.file.spi.FileSystemProvider.newInputStream(FileSystemProvider.java:384)
        at java.nio.file.Files.newInputStream(Files.java:152)
        at org.elasticsearch.tools.launchers.JvmOptionsParser.main(JvmOptionsParser.java:60)
 

解決：
(1) 切換到root賬戶，修改/usr/local/elasticsearch-6.4.3/config/jvm.options檔案的Xms和Xmx的配置：

-Xms512m
-Xmx512m

(2) 修改檔案許可權

sudo chmod 644 jvm.options

• root賬號啟動報錯

org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root
        at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:140) ~[elasticsearch-6.4.3.jar:6.4.3]
        at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:127) ~[elasticsearch-6.4.3.jar:6.4.3]
        at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-6.4.3.jar:6.4.3]
        at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-6.4.3.jar:6.4.3]
        at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.4.3.jar:6.4.3]
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:93) ~[elasticsearch-6.4.3.jar:6.4.3]
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:86) ~[elasticsearch-6.4.3.jar:6.4.3]
Caused by: java.lang.RuntimeException: can not run elasticsearch as root
        at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:104) ~[elasticsearch-6.4.3.jar:6.4.3]
        at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:171) ~[elasticsearch-6.4.3.jar:6.4.3]
        at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:326) ~[elasticsearch-6.4.3.jar:6.4.3]
        at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:136) ~[elasticsearch-6.4.3.jar:6.4.3]
        ... 6 more
 

解決：切換到普通使用者重啟啟動。

• 啟動過程中提示

ERROR: [1] bootstrap checks failed
[1]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[2018-11-23T10:00:28,057][INFO ][o.e.n.Node               ] [mQQdX2p] stopping ...
[2018-11-23T10:00:28,100][INFO ][o.e.n.Node               ] [mQQdX2p] stopped
[2018-11-23T10:00:28,101][INFO ][o.e.n.Node               ] [mQQdX2p] closing ...
[2018-11-23T10:00:28,111][INFO ][o.e.n.Node               ] [mQQdX2p] closed

解決：
(1) 修改配置sysctl.conf

vim /etc/sysctl.conf

(2) 新增下面配置：

vm.max_map_count=655360

(3) 配置生效：

sysctl -p

六、設定外網訪問

(1) 進入/usr/local/elasticsearch-6.4.3/config目錄，編輯檔案elasticsearch.yml，增加配置network.host: 0.0.0.0
命令如下：

vim  elasticsearch.yml

Insert進入編輯模式，增加network.host: 0.0.0.0，修改完成之後Esc退出編輯模式，執行:wq儲存並退出，重啟啟動即可。
啟動成功後，在瀏覽器訪問：http://IP地址:9200/，出現以下配置表示安裝成功。

name	"mQQdX2p"
cluster_name	"elasticsearch"
cluster_uuid	"em-fVPdIRLeG4BZAkdRarA"
version	
number	"6.4.3"
build_flavor	"default"
build_type	"tar"
build_hash	"fe40335"
build_date	"2018-10-30T23:17:19.084789Z"
build_snapshot	false
lucene_version	"7.4.0"
minimum_wire_compatibility_version	"5.6.0"
minimum_index_compatibility_version	"5.0.0"
tagline	"You Know, for Search"

七、後臺執行

為了在關閉終端的時候，讓Elasticsearch繼續保持執行，需要設定使es在後臺執行。
切換到安裝目錄下，執行。

bin/elasticsearch -d