1、Elasticsearch 6.x版本全文检索学习之分布式特性介绍。
1）、Elasticsearch支持集群默认，是一个分布式系统，其好处主要有两个。
a、增大系统容量，如内存、磁盘、使得es集群可以支持PB级别的数据。
b、提供系统可用性，即使部分节点停止服务，整个集群依然可以正常服务。
2）、Elasticsearch集群由多个es实例组成。
a、不同集群通过集群名字来区分，可以通过cluster.name进行修改，默认为elasticsearch。
b、每个es实例本质上是一个JVM进程，且有自己的名字，通过node.name进行修改。
2、cerebro的安装与运行。Github地址：https://github.com/lmenezes/cerebro。下载，安装，部署。
1 [root@slaver4 package]# wget https://github.com/lmenezes/cerebro/releases/download/v0.7.2/cerebro-0.7.2.tgz 2 --2019-11-01 09:20:22-- https://github.com/lmenezes/cerebro/releases/download/v0.7.2/cerebro-0.7.2.tgz 3 正在解析主机 github.com (github.com)... 13.250.177.223 4 正在连接 github.com (github.com)|13.250.177.223|:443... 已连接。 5 已发出 HTTP 请求，正在等待回应... 302 Found 6 位置：https://github-production-release-asset-2e65be.s3.amazonaws.com/54560347/a5bf160e-d454-11e7-849b-758511101a2f?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20191101%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20191101T012023Z&X-Amz-Expires=300&X-Amz-Signature=8b121e4e2a72d997441ebf78e2d8bea9deeeb322d1a3fbc676bc8398099b73a3&X-Amz-SignedHeaders=host&actor_id=0&response-content-disposition=attachment%3B%20filename%3Dcerebro-0.7.2.tgz&response-content-type=application%2Foctet-stream [跟随至新的 URL] 7 --2019-11-01 09:20:23-- https://github-production-release-asset-2e65be.s3.amazonaws.com/54560347/a5bf160e-d454-11e7-849b-758511101a2f?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20191101%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20191101T012023Z&X-Amz-Expires=300&X-Amz-Signature=8b121e4e2a72d997441ebf78e2d8bea9deeeb322d1a3fbc676bc8398099b73a3&X-Amz-SignedHeaders=host&actor_id=0&response-content-disposition=attachment%3B%20filename%3Dcerebro-0.7.2.tgz&response-content-type=application%2Foctet-stream 8 正在解析主机 github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)... 52.216.130.123 9 正在连接 github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)|52.216.130.123|:443... 已连接。 10 已发出 HTTP 请求，正在等待回应... 200 OK 11 长度：52121825 (50M) [application/octet-stream] 12 正在保存至: “cerebro-0.7.2.tgz” 13 14 100%[======================================================================================================================================================================================>] 52,121,825 1.34MB/s 用时 30s 15 16 2019-11-01 09:20:55 (1.65 MB/s) - 已保存 “cerebro-0.7.2.tgz” [52121825/52121825]) 17 18 [root@slaver4 package]# ls 19 cerebro-0.7.2.tgz elasticsearch-6.7.0.tar.gz erlang-solutions-1.0-1.noarch.rpm filebeat-6.7.0-linux-x86_64.tar.gz kibana-6.7.0-linux-x86_64.tar.gz logstash-6.7.0.tar.gz materials rabbitmq-server-3.5.1-1.noarch.rpm 20 [root@slaver4 package]# tar -zxvf cerebro-0.7.2.tgz -C /home/hadoop/soft/
将cerebro赋予新创建的elsearch用户，用户组。
1 [root@slaver4 package]# cd ../soft/ 2 [root@slaver4 soft]# ls 3 cerebro-0.7.2 elasticsearch-6.7.0 filebeat-6.7.0-linux-x86_64 kibana-6.7.0-linux-x86_64 logstash-6.7.0 4 [root@slaver4 soft]# chown elsearch:elsearch cerebro-0.7.2/ 5 [root@slaver4 soft]# su elsearch 6 [elsearch@slaver4 soft]$ ls 7 cerebro-0.7.2 elasticsearch-6.7.0 filebeat-6.7.0-linux-x86_64 kibana-6.7.0-linux-x86_64 logstash-6.7.0 8 [elsearch@slaver4 soft]$ ll 9 总用量 0 10 drwxr-xr-x. 5 elsearch elsearch 57 11月 28 2017 cerebro-0.7.2 11 drwxr-xr-x. 9 elsearch elsearch 155 10月 25 15:09 elasticsearch-6.7.0 12 drwxr-xr-x. 6 elsearch elsearch 252 10月 26 11:22 filebeat-6.7.0-linux-x86_64 13 drwxr-xr-x. 13 elsearch elsearch 246 10月 25 16:13 kibana-6.7.0-linux-x86_64 14 drwxr-xr-x. 12 elsearch elsearch 255 10月 26 14:37 logstash-6.7.0 15 [elsearch@slaver4 soft]$
安装了jvm即java就可以运行了。我启动报了如下错误，修改一下日志记录的路径。
1 [elsearch@slaver4 bin]$ ./cerebro 2 09:27:05,150 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy] 3 09:27:05,151 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml] 4 09:27:05,151 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Found resource [logback.xml] at [file:/home/hadoop/soft/cerebro-0.7.2/conf/logback.xml] 5 09:27:05,363 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - debug attribute not set 6 09:27:05,371 |-INFO in ch.qos.logback.core.joran.action.ConversionRuleAction - registering conversion word coloredLevel with class [play.api.libs.logback.ColoredLevel] 7 09:27:05,371 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.FileAppender] 8 09:27:05,381 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [FILE] 9 09:27:05,393 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property 10 09:27:05,427 |-INFO in ch.qos.logback.core.FileAppender[FILE] - File property is set to [./logs/application.log] 11 09:27:05,428 |-ERROR in ch.qos.logback.core.FileAppender[FILE] - Failed to create parent directories for [/home/hadoop/soft/cerebro-0.7.2/./logs/application.log] 12 09:27:05,429 |-ERROR in ch.qos.logback.core.FileAppender[FILE] - openFile(./logs/application.log,true) call failed. java.io.FileNotFoundException: ./logs/application.log (没有那个文件或目录) 13 at java.io.FileNotFoundException: ./logs/application.log (没有那个文件或目录) 14 at at java.io.FileOutputStream.open0(Native Method) 15 at at java.io.FileOutputStream.open(FileOutputStream.java:270) 16 at at java.io.FileOutputStream.<init>(FileOutputStream.java:213) 17 at at ch.qos.logback.core.recovery.ResilientFileOutputStream.<init>(ResilientFileOutputStream.java:26) 18 at at ch.qos.logback.core.FileAppender.openFile(FileAppender.java:186) 19 at at ch.qos.logback.core.FileAppender.start(FileAppender.java:121) 20 at at ch.qos.logback.core.joran.action.AppenderAction.end(AppenderAction.java:90) 21 at at ch.qos.logback.core.joran.spi.Interpreter.callEndAction(Interpreter.java:309) 22 at at ch.qos.logback.core.joran.spi.Interpreter.endElement(Interpreter.java:193) 23 at at ch.qos.logback.core.joran.spi.Interpreter.endElement(Interpreter.java:179) 24 at at ch.qos.logback.core.joran.spi.EventPlayer.play(EventPlayer.java:62) 25 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:155) 26 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:142) 27 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:103) 28 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:53) 29 at at ch.qos.logback.classic.util.ContextInitializer.configureByResource(ContextInitializer.java:75) 30 at at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:150) 31 at at org.slf4j.impl.StaticLoggerBinder.init(StaticLoggerBinder.java:84) 32 at at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:55) 33 at at play.api.libs.logback.LogbackLoggerConfigurator.configure(LogbackLoggerConfigurator.scala:80) 34 at at play.api.libs.logback.LogbackLoggerConfigurator.configure(LogbackLoggerConfigurator.scala:62) 35 at at play.api.inject.guice.GuiceApplicationBuilder$$anonfun$applicationModule$1.apply(GuiceApplicationBuilder.scala:102) 36 at at play.api.inject.guice.GuiceApplicationBuilder$$anonfun$applicationModule$1.apply(GuiceApplicationBuilder.scala:102) 37 at at scala.Option.foreach(Option.scala:257) 38 at at play.api.inject.guice.GuiceApplicationBuilder.applicationModule(GuiceApplicationBuilder.scala:101) 39 at at play.api.inject.guice.GuiceBuilder.injector(GuiceInjectorBuilder.scala:181) 40 at at play.api.inject.guice.GuiceApplicationBuilder.build(GuiceApplicationBuilder.scala:123) 41 at at play.api.inject.guice.GuiceApplicationLoader.load(GuiceApplicationLoader.scala:21) 42 at at play.core.server.ProdServerStart$.start(ProdServerStart.scala:47) 43 at at play.core.server.ProdServerStart$.main(ProdServerStart.scala:22) 44 at at play.core.server.ProdServerStart.main(ProdServerStart.scala) 45 09:27:05,429 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender] 46 09:27:05,431 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT] 47 09:27:05,431 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property 48 09:27:05,439 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [play] to INFO 49 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [application] to INFO 50 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebean.config.PropertyMapLoader] to OFF 51 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebeaninternal.server.core.XmlConfigLoader] to OFF 52 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebeaninternal.server.lib.BackgroundThread] to OFF 53 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.gargoylesoftware.htmlunit.javascript] to OFF 54 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to ERROR 55 09:27:05,440 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT] 56 09:27:05,441 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [FILE] to Logger[ROOT] 57 09:27:05,441 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration. 58 09:27:05,442 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator@53aac487 - Registering current configuration as safe fallback point 59 60 09:27:05,150 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy] 61 09:27:05,151 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml] 62 09:27:05,151 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Found resource [logback.xml] at [file:/home/hadoop/soft/cerebro-0.7.2/conf/logback.xml] 63 09:27:05,363 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - debug attribute not set 64 09:27:05,371 |-INFO in ch.qos.logback.core.joran.action.ConversionRuleAction - registering conversion word coloredLevel with class [play.api.libs.logback.ColoredLevel] 65 09:27:05,371 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.FileAppender] 66 09:27:05,381 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [FILE] 67 09:27:05,393 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property 68 09:27:05,427 |-INFO in ch.qos.logback.core.FileAppender[FILE] - File property is set to [./logs/application.log] 69 09:27:05,428 |-ERROR in ch.qos.logback.core.FileAppender[FILE] - Failed to create parent directories for [/home/hadoop/soft/cerebro-0.7.2/./logs/application.log] 70 09:27:05,429 |-ERROR in ch.qos.logback.core.FileAppender[FILE] - openFile(./logs/application.log,true) call failed. java.io.FileNotFoundException: ./logs/application.log (没有那个文件或目录) 71 at java.io.FileNotFoundException: ./logs/application.log (没有那个文件或目录) 72 at at java.io.FileOutputStream.open0(Native Method) 73 at at java.io.FileOutputStream.open(FileOutputStream.java:270) 74 at at java.io.FileOutputStream.<init>(FileOutputStream.java:213) 75 at at ch.qos.logback.core.recovery.ResilientFileOutputStream.<init>(ResilientFileOutputStream.java:26) 76 at at ch.qos.logback.core.FileAppender.openFile(FileAppender.java:186) 77 at at ch.qos.logback.core.FileAppender.start(FileAppender.java:121) 78 at at ch.qos.logback.core.joran.action.AppenderAction.end(AppenderAction.java:90) 79 at at ch.qos.logback.core.joran.spi.Interpreter.callEndAction(Interpreter.java:309) 80 at at ch.qos.logback.core.joran.spi.Interpreter.endElement(Interpreter.java:193) 81 at at ch.qos.logback.core.joran.spi.Interpreter.endElement(Interpreter.java:179) 82 at at ch.qos.logback.core.joran.spi.EventPlayer.play(EventPlayer.java:62) 83 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:155) 84 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:142) 85 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:103) 86 at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:53) 87 at at ch.qos.logback.classic.util.ContextInitializer.configureByResource(ContextInitializer.java:75) 88 at at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:150) 89 at at org.slf4j.impl.StaticLoggerBinder.init(StaticLoggerBinder.java:84) 90 at at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:55) 91 at at play.api.libs.logback.LogbackLoggerConfigurator.configure(LogbackLoggerConfigurator.scala:80) 92 at at play.api.libs.logback.LogbackLoggerConfigurator.configure(LogbackLoggerConfigurator.scala:62) 93 at at play.api.inject.guice.GuiceApplicationBuilder$$anonfun$applicationModule$1.apply(GuiceApplicationBuilder.scala:102) 94 at at play.api.inject.guice.GuiceApplicationBuilder$$anonfun$applicationModule$1.apply(GuiceApplicationBuilder.scala:102) 95 at at scala.Option.foreach(Option.scala:257) 96 at at play.api.inject.guice.GuiceApplicationBuilder.applicationModule(GuiceApplicationBuilder.scala:101) 97 at at play.api.inject.guice.GuiceBuilder.injector(GuiceInjectorBuilder.scala:181) 98 at at play.api.inject.guice.GuiceApplicationBuilder.build(GuiceApplicationBuilder.scala:123) 99 at at play.api.inject.guice.GuiceApplicationLoader.load(GuiceApplicationLoader.scala:21) 100 at at play.core.server.ProdServerStart$.start(ProdServerStart.scala:47) 101 at at play.core.server.ProdServerStart$.main(ProdServerStart.scala:22) 102 at at play.core.server.ProdServerStart.main(ProdServerStart.scala) 103 09:27:05,429 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender] 104 09:27:05,431 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT] 105 09:27:05,431 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property 106 09:27:05,439 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [play] to INFO 107 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [application] to INFO 108 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebean.config.PropertyMapLoader] to OFF 109 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebeaninternal.server.core.XmlConfigLoader] to OFF 110 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebeaninternal.server.lib.BackgroundThread] to OFF 111 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.gargoylesoftware.htmlunit.javascript] to OFF 112 09:27:05,440 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to ERROR 113 09:27:05,440 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT] 114 09:27:05,441 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [FILE] to Logger[ROOT] 115 09:27:05,441 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration. 116 09:27:05,442 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator@53aac487 - Registering current configuration as safe fallback point 117 09:27:05,457 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - debug attribute not set 118 09:27:05,457 |-INFO in ch.qos.logback.core.joran.action.ConversionRuleAction - registering conversion word coloredLevel with class [play.api.libs.logback.ColoredLevel] 119 09:27:05,457 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.FileAppender] 120 09:27:05,457 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [FILE] 121 09:27:05,458 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property 122 09:27:05,459 |-INFO in ch.qos.logback.core.FileAppender[FILE] - File property is set to [/home/hadoop/soft/cerebro-0.7.2/logs/application.log] 123 09:27:05,459 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender] 124 09:27:05,459 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT] 125 09:27:05,461 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property 126 09:27:05,473 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [play] to INFO 127 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [application] to INFO 128 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebean.config.PropertyMapLoader] to OFF 129 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebeaninternal.server.core.XmlConfigLoader] to OFF 130 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.avaje.ebeaninternal.server.lib.BackgroundThread] to OFF 131 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.gargoylesoftware.htmlunit.javascript] to OFF 132 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to ERROR 133 09:27:05,474 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT] 134 09:27:05,474 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [FILE] to Logger[ROOT] 135 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration. 136 09:27:05,474 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator@534a5a98 - Registering current configuration as safe fallback point 137 138 [info] play.api.Play - Application started (Prod) 139 [info] p.c.s.NettyServer - Listening for HTTP on /0:0:0:0:0:0:0:0:9000
修改vim logback.xml，这个配置文件，<file>/home/hadoop/soft/cerebro-0.7.2/logs/application.log</file>，配置成自己的日志文件路径即可。
1 <configuration> 2 3 <conversionRule conversionWord="coloredLevel" converterClass="play.api.libs.logback.ColoredLevel"/> 4 5 <appender name="FILE" class="ch.qos.logback.core.FileAppender"> 6 <file>/home/hadoop/soft/cerebro-0.7.2/logs/application.log</file> 7 <encoder> 8 <pattern>%date - [%level] - from %logger in %thread %n%message%n%xException%n</pattern> 9 </encoder> 10 </appender> 11 12 <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> 13 <encoder> 14 <pattern>%coloredLevel %logger{15} - %message%n%xException{5}</pattern> 15 </encoder> 16 </appender> 17 18 <logger name="play" level="INFO"/> 19 <logger name="application" level="INFO"/> 20 21 <!-- Off these ones as they are annoying, and anyway we manage configuration ourself --> 22 <logger name="com.avaje.ebean.config.PropertyMapLoader" level="OFF"/> 23 <logger name="com.avaje.ebeaninternal.server.core.XmlConfigLoader" level="OFF"/> 24 <logger name="com.avaje.ebeaninternal.server.lib.BackgroundThread" level="OFF"/> 25 <logger name="com.gargoylesoftware.htmlunit.javascript" level="OFF"/> 26 27 <root level="ERROR"> 28 <appender-ref ref="STDOUT"/> 29 <appender-ref ref="FILE"/> 30 </root> 31 32 </configuration>
重新启动，如下所示：
1 [root@slaver4 bin]$ ./cerebro 2 [info] play.api.Play - Application started (Prod) 3 [info] p.c.s.NettyServer - Listening for HTTP on /0:0:0:0:0:0:0:0:9000
现在启动你的Elasticseach。访问地址http://192.168.110.133:9000，界面如下所示：
连上如下所示：
3、Elasticsearch快速构建集群。指定集群名称cluster.name、path.data的名称、node.name的名称、http.port端口号。最后的-d参数在后台运行。
1 [elsearch@slaver4 bin]$ ./elasticsearch -Ecluster.name=my_cluster -Epath.data=my_cluster_node1 -Enode.name=node1 -Ehttp.port=5200 -d 2 OpenJDK 64-Bit Server VM warning: If the number of processors is expected to increase from one, then you should configure the number of parallel GC threads appropriately using -XX:ParallelGCThreads=N 3 [elsearch@slaver4 bin]$
4、Cluster state。
答：Elasticsearch集群相关的数据称为cluster state，主要记录如下信息。cluster state有版本控制的，创建索引以后，版本更新。
节点信息，比如节点名称、连接地址等等。
索引信息，比如索引名称、配置等等。
五角星代表的是主节点、圆代表的是Coordinating节点、方框代表的是data节点。
5、Master Node。
答：可以修改cluster state的节点称为master节点，一个集群只能有一个。
cluster state存储在每个节点上，master维护最新版本并同步给其他节点。
master节点是通过集群中所有节点选举产生的，可以被选举的节点称为master-eligible节点，相关配置如下所示：node.master:true。
6、Coordinating Node。
答：处理请求的节点即为coordinating节点，该节点为所有节点的默认角色，不能取消。
路由请求到正确的节点处理，比如创建索引的请求到master节点。
7、Data Node。
答：存储数据的节点即为data节点，默认节点都是data类型，相关配置如下。node.data:true。
8、解决单点问题，如果单节点，一个节点挂了，集群停止服务，可以通过新增节点保障集群健壮性，运行如下命令，可以启动一个es节点实例。启动多个节点依次类推。
./elasticsearch -Ecluster.name=my_cluster -Epath.data=my_cluster_node2 -Enode.name=node2 -Ehttp.port=5300 -d。
1 [root@slaver4 ~]# su elsearch 2 [elsearch@slaver4 root]$ cd /home/hadoop/soft/ 3 [elsearch@slaver4 soft]$ ls 4 cerebro-0.7.2 elasticsearch-6.7.0 filebeat-6.7.0-linux-x86_64 kibana-6.7.0-linux-x86_64 logstash-6.7.0 5 [elsearch@slaver4 soft]$ cd elasticsearch-6.7.0/ 6 [elsearch@slaver4 elasticsearch-6.7.0]$ ls 7 bin config data lib LICENSE.txt logs modules my_cluster_node1 NOTICE.txt plugins README.textile 8 [elsearch@slaver4 elasticsearch-6.7.0]$ cd bin/ 9 [elsearch@slaver4 bin]$ ./elasticsearch -Ecluster.name=my_cluster -Epath.data=my_cluster_node2 -Enode.name=node2 -Ehttp.port=5300 -d 10 OpenJDK 64-Bit Server VM warning: If the number of processors is expected to increase from one, then you should configure the number of parallel GC threads appropriately using -XX:ParallelGCThreads=N 11 [elsearch@slaver4 bin]$ ./elasticsearch -Ecluster.name=my_cluster -Epath.data=my_cluster_node1 -Enode.name=node1 -Ehttp.port=5200 -d 12 OpenJDK 64-Bit Server VM warning: If the number of processors is expected to increase from one, then you should configure the number of parallel GC threads appropriately using -XX:ParallelGCThreads=N 13 [elsearch@slaver4 bin]$
如果使用的是虚拟机，一定要将此配置修改为这样，不然你是将节点加不到一个集群里面的。
[elsearch@slaver4 config]$ vim elasticsearch.yml
1 network.host: 0.0.0.0
效果如下所示：
9、提供系统可用性。
答：服务可用性:2个节点的情况下，允许其中1个节点停止服务。
数据可用性。a、引入副本（Replication）解决。b、每个节点上都有完备的数据。
10、elasticsearch的副本和分片。
如何将数据分布到所有节点上，引入分片（Shard）解决问题。
分片是ES支持PB级数据的基石，特点：a、分片存储了部分数据，可以分布于任意节点上。b、分片数在索引创建时指定且后续不允许再更改，默认为5个。c、分片有主分片和副本分片之分，以实现数据的高可用。d、副本分片的数据由主分片同步，可以有多个，从而提高读取的吞吐量。
创建索引的两种方式，第一种，直接使用api进行创建即可，如下所示：
在集群中test_index索引，创建3个分片和1个副本。Primary Shard主分片、Replication Shard副本分片。
# 在集群中test_index索引，创建3个分片和1个副本。Primary Shard主分片、Replication Shard副本分片。 PUT test_index { "settings": { "number_of_shards": 3, "number_of_replicas": 1 } }
方式二，直接使用页面创建即可，如下所示：
实线表示主分片，虚线表示副分片，主分片和副本分片一一对应。效果如下所示：
11、如果集群是三个节点，此时增加节点是否能提高test_index的数据容量？
答：不能，因为只有3个分片，已经分布在3台节点上，新增的节点无法利用。
12、如果集群是三个节点，此时增加副本数是否能提高test_index的读取吞吐量？。
答：不能，因为新增的副本是分布在3个节点上，还是利用了同样的资源，如果要增加吞吐量，还需要增加节点。
13、分片数的设定非常重要，需要提前规划好。
分片数太少，导致后续无法通过增加节点实现水平扩容。
分片数过大，导致一个节点上分布多个分片，造成资源浪费，同时会影响查询性能。
14、集群状态Cluster Health。三种状态只是代表分片的工作状态，并不是代表整个es集群是否能够对外提供服务。Rest api获取状态：GET _cluster/health。
通过如下api可以查看集群健康状况，包括以下三种：
a、green 健康状态，指所有主副分片都正常分配。
b、yellow 指所有主分片都正常分配，但是有副本分片未正常分配。
c、red 有主分片未分配。但是可以访问该集群的。
Rest api获取状态：GET _cluster/health。
15、elasticsearch故障转移。
假设集群由3个节点组成，此时集群状态是green。初始状态，node1节点（P0、R1分片）、node2节点（P1、R2分片）、node3节点（P2、R0分片）。
如果node1（node1节点是主节点）所在机器宕机导致服务终止，此时集群会如何处理？
第一步、node2和node3发现node1无法响应一段时间后会发起master选举，比如这里选举node2为master节点，此时由于主分片P0下线，集群状态变为red。
第二步、node2发现主分片P0未分配，将R0提升为主分片。此时由于所有主分片都正常分配，集群状态变为yellow。node2节点（P1、R2分片）、node3节点（P2、P0分片）。
第三步、node2发现主分片P0和P1生成新的副本，集群状态变为green。node2节点（P1、R2、R0分片）、node3节点（P2、P0、R1分片）。
16、elasticsearch文档分布式存储。
文档最终会存储在分片上，elasticsearch使用文档存储算法。假设doc1存储到分片P1，doc1是如何存储到分片P1的呢，需要文档到分片的映射算法，目的使得文档均匀分布在所有分片上， 以充分利用资源。elasticsearch的分布式文档存储方案使用的是hash算法。
待续......