Hadoop 2.x HDFS和YARN的啟動(dòng)方式
一.三種啟動(dòng)方式介紹
方式一：逐一啟動(dòng)(實(shí)際生產(chǎn)環(huán)境中的啟動(dòng)方式)
- hadoop-daemon.sh start|stop namenode|datanode| journalnode
- yarn-daemon.sh start |stop resourcemanager|nodemanager
方式二：分開啟動(dòng)
- start-dfs.sh
- start-yarn.sh
方式三：一起啟動(dòng)
- start-all.sh
二.腳本解讀
start-dfs.sh腳本：
(1) 通過命令bin/hdfs getconf –namenodes查看namenode在那些節(jié)點(diǎn)上
(2) 通過ssh方式登錄到遠(yuǎn)程主機(jī)，啟動(dòng)hadoop-deamons.sh腳本
(3) hadoop-deamon.sh腳本啟動(dòng)slaves.sh腳本
(4) slaves.sh腳本啟動(dòng)hadoop-deamon.sh腳本，再逐一啟動(dòng)
start-all.sh腳本：
說明：start-all.sh實(shí)際上是調(diào)用sbin/start-dfs.sh腳本和sbin/start-yarn.sh腳本
三.三種啟動(dòng)方式的關(guān)系
start-all.sh其實(shí)調(diào)用start-dfs.sh和start-yarn.sh
start-dfs.sh調(diào)用hadoop-deamon.sh
start-yarn.sh調(diào)用yarn-deamon.sh
如下圖：
四.為什么要設(shè)置ssh協(xié)議
當(dāng)執(zhí)行start-dfs.sh腳本時(shí)，會(huì)調(diào)用slaves.sh腳本，通過ssh協(xié)議無密碼登陸到其他節(jié)點(diǎn)去啟動(dòng)進(jìn)程。
為了能自動(dòng)啟動(dòng)遠(yuǎn)程節(jié)點(diǎn)的進(jìn)程，需要進(jìn)行免密碼登錄。
五.采用第二種啟動(dòng)方式
上面已經(jīng)配置好了ssh公鑰登錄，接下來用第二種啟動(dòng)方式啟動(dòng)
Step1:先停止所以進(jìn)程(如果已經(jīng)啟動(dòng))
- [hadoop@hadoop-yarn hadoop-2.2.0]$sbin/yarn-daemon.sh stop nodemanager
- [hadoop@hadoop-yarn hadoop-2.2.0]$sbin/yarn-daemon.sh stop resourcemanager
- [hadoop@hadoop-yarn hadoop-2.2.0]$sbin/hadoop-daemon.sh stop datanode
- [hadoop@hadoop-yarn hadoop-2.2.0]$sbin/hadoop-daemon.sh stop secondarynamenode
- [hadoop@hadoop-yarn hadoop-2.2.0]$sbin/hadoop-daemon.sh stop namenode
Step2:啟動(dòng)所以進(jìn)程
- [hadoop@hadoop-yarn hadoop-2.2.0]$sbin/start-dfs.sh
- [hadoop@hadoop-yarn hadoop-2.2.0]$ sbin/start-yarn.sh
Step3:查看管理界面
