目录
优化&新特性&HAYARN-HA工作机制
1）官方文档：
http://hadoop.apache.org/docs/r3.1.3/hadoop-yarn/hadoop-yarn-site/ResourceManagerHA.html
2）YARN-HA工作机制
配置YARN-HA集群
1）环境准备
- （1）修改IP
- （2）修改主机名及主机名和IP地址的映射
- （3）关闭防火墙
- （4）ssh免密登录
- （5）安装JDK，配置环境变量等
- （6）配置Zookeeper集群
2）规划集群
| hadoop102 | hadoop103 | hadoop104 |
| NameNode | NameNode | NameNode |
| JournalNode | JournalNode | JournalNode |
| DataNode | DataNode | DataNode |
| ZK | ZK | ZK |
| ResourceManager | ResourceManager | ResourceManager |
| NodeManager | NodeManager | NodeManager |
3）具体配置
（1）yarn-site.xml
<!-- 启用resourcemanager ha -->
<property>
<name>yarn.resourcemanager.ha.enabled</name>
<value>true</value>
</property>
<!-- 声明三台resourcemanager的地址 -->
<property>
<name>yarn.resourcemanager.cluster-id</name>
<value>cluster-yarn1</value>
</property>
<!--指定resourcemanager的逻辑列表-->
<property>
<name>yarn.resourcemanager.ha.rm-ids</name>
<value>rm1,rm2,rm3</value>
</property>
<!-- ========== rm1的配置 ========== -->
<!-- 指定rm1的主机名 -->
<property>
<name>yarn.resourcemanager.hostname.rm1</name>
<value>hadoop102</value>
</property>
<!-- 指定rm1的web端地址 -->
<property>
<name>yarn.resourcemanager.webapp.address.rm1</name>
<value>hadoop102:8088</value>
</property>
<!-- 指定rm1的内部通信地址 -->
<property>
<name>yarn.resourcemanager.address.rm1</name>
<value>hadoop102:8032</value>
</property>
<!-- 指定AM向rm1申请资源的地址 -->
<property>
<name>yarn.resourcemanager.scheduler.address.rm1</name>
<value>hadoop102:8030</value>
</property>
<!-- 指定供NM连接的地址 -->
<property>
<name>yarn.resourcemanager.resource-tracker.address.rm1</name>
<value>hadoop102:8031</value>
</property>
<!-- ========== rm2的配置 ========== -->
<!-- 指定rm2的主机名 -->
<property>
<name>yarn.resourcemanager.hostname.rm2</name>
<value>hadoop103</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address.rm2</name>
<value>hadoop103:8088</value>
</property>
<property>
<name>yarn.resourcemanager.address.rm2</name>
<value>hadoop103:8032</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address.rm2</name>
<value>hadoop103:8030</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address.rm2</name>
<value>hadoop103:8031</value>
</property>
<!-- ========== rm3的配置 ========== -->
<!-- 指定rm3的主机名 -->
<property>
<name>yarn.resourcemanager.hostname.rm3</name>
<value>hadoop104</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address.rm3</name>
<value>hadoop104:8088</value>
</property>
<property>
<name>yarn.resourcemanager.address.rm3</name>
<value>hadoop104:8032</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address.rm3</name>
<value>hadoop104:8030</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address.rm3</name>
<value>hadoop104:8031</value>
</property>
<!-- 指定zookeeper集群的地址 -->
<property>
<name>yarn.resourcemanager.zk-address</name>
<value>hadoop102:2181,hadoop103:2181,hadoop104:2181</value>
</property>
<!-- 启用自动恢复 -->
<property>
<name>yarn.resourcemanager.recovery.enabled</name>
<value>true</value>
</property>
<!-- 指定resourcemanager的状态信息存储在zookeeper集群 -->
<property>
<name>yarn.resourcemanager.store.class</name>
<value>org.apache.hadoop.yarn.server.resourcemanager.recovery.ZKRMStateStore</value>
</property>
4）启动hdfs
[hadoop@hadoop102 ~]$ start-dfs.sh
5）启动YARN
（1）在hadoop102或者hadoop103中执行：
[hadoop@hadoop102 ~]$ start-yarn.sh
（2）查看服务状态
[hadoop@hadoop102 ~]$ yarn rmadmin -getServiceState rm1
（3）可以去zkCli.sh客户端查看ResourceManager选举锁节点内容：
[hadoop@hadoop102 ~]$ zkCli.sh
[zk: localhost:2181(CONNECTED) 16] get -s /yarn-leader-election/cluster-yarn1/ActiveStandbyElectorLock
cluster-yarn1rm1
cZxid = 0x100000022
ctime = Tue Jul 14 17:06:44 CST 2020
mZxid = 0x100000022
mtime = Tue Jul 14 17:06:44 CST 2020
pZxid = 0x100000022
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x30000da33080005
dataLength = 20
numChildren = 0
（4）web端查看hadoop102:8088和hadoop103:8088的YARN的状态，和NameNode对比，查看区别
