Elasticsearch-02.安装Elasticsearch

Elasticsearch-02.安装Elasticsearch

本系列博客基于Elasticsearch 7.0进行编写，旨在对自己的所学进行结构化输出，查漏补缺。

安装Elasticsearch

Elasticsearch可以零配置启动，会下载解压压缩包，就能启起来。

下载地址：
https://www.elastic.co/cn/downloads/elasticsearch

启动bin目录下的elasticsearch/elasticsearch.bat的启动脚本。

访问http://localhost:9200/

{
  "name" : "DESKTOP-QFLTHE7",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "hc3eDw6ARmO2vLliKw5Tjg",
  "version" : {
    "number" : "7.7.0",
    "build_flavor" : "default",
    "build_type" : "zip",
    "build_hash" : "81a1e9eda8e6183f5237786246f6dced26a10eaf",
    "build_date" : "2020-05-12T02:01:37.602180Z",
    "build_snapshot" : false,
    "lucene_version" : "8.5.1",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

JDK8下的启动告警

future versions of Elasticsearch will require Java 11; your Java version from [C:\Program Files\Java\jdk1.8.0_202\jre] does not meet this requirement
future versions of Elasticsearch will require Java 11; your Java version from [C:\Program Files\Java\jdk1.8.0_202\jre] does not meet this requirement
Warning: with JDK 8 on Windows, Elasticsearch may be unable to derive correct
  ergonomic settings due to a JDK issue (JDK-8074459). Please use a newer
  version of Java.
Warning: MaxDirectMemorySize may have been miscalculated due to JDK-8074459.
  Please use a newer version of Java or set MaxDirectMemorySize explicitly.

这是因为环境变量中已配置jdk，Elasticsearch启动时默认使用环境变量中的配置，从上面的目录结构中我们已经看到Elasticsearch自带java环境，此时需要更Elasticsearch启动文件，让Elasticsearch使用自带的jdk环境，

elasticsearch-env.bat :39~46

if defined JAVA_HOME (
  set JAVA="%JAVA_HOME%\bin\java.exe"
  set JAVA_TYPE=JAVA_HOME
) else (
  set JAVA="%ES_HOME%\jdk\bin\java.exe"
  set JAVA_HOME="%ES_HOME%\jdk"
  set JAVA_TYPE=bundled jdk
)

修改为

  set JAVA="%ES_HOME%\jdk\bin\java.exe"
  set JAVA_HOME="%ES_HOME%\jdk"
  set JAVA_TYPE=bundled jdk

UseConcMarkSweepGC弃用告警

OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.

这是因为从jdk9开始cms垃圾收集器已经被标注为弃用了，可以在elasticsearch安装目录下的config下找到jvm.options文件，用记事本打开，将-XX:+UseConcMarkSweepGC 修改为 -XX:+UseG1GC

参考资料

[1] 官网教程.Getting started with Elasticsearch.https://www.elastic.co/guide/en/elasticsearch/reference/current/getting-started.html