目录

  一、实验

1.环境

2.Yarn 节点扩容

3.Yarn 节点缩容

二、问题

1.yarn启动服务报错

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  一、实验

1.环境

（1）主机

表1  主机

主机	架构	软件	版本	IP	备注
hadoop	NameNode （已部署） SecondaryNameNode （已部署） ResourceManager（已部署）	hadoop	2.7.7	192.168.204.50
node01	DataNode（已部署） NodeManager（已部署）	hadoop	2.7.7	192.168.204.51
node02	DataNode（已部署） NodeManager（已部署）	hadoop	2.7.7	192.168.204.52
node03	DataNode（已部署） NodeManager（已部署）	hadoop	2.7.7	192.168.204.53
node05	NodeManager	hadoop	2.7.7	192.168.204.55

（2）查看jps

hadoop节点

[root@hadoop hadoop]# jps

node01节点

node02节点

node03节点

（3） 查看节点

[root@hadoop hadoop]# ./bin/yarn node -list
24/03/14 13:40:21 INFO client.RMProxy: Connecting to ResourceManager at hadoop/192.168.204.50:8032
Total Nodes:3
         Node-Id             Node-State Node-Http-Address       Number-of-Running-Containers
    node01:40551                RUNNING       node01:8042                                  0
    node02:46073                RUNNING       node02:8042                                  0
    node03:40601                RUNNING       node03:8042                                  0

2.Yarn 节点扩容

（1）查看IP

地址为192.168.204.55

[root@localhost ~]# ip addr

 （2）安全机制

查看

[root@localhost ~]# sestatus

关闭

[root@localhost ~]# vim /etc/selinux/config
……
SELINUX=disabled
……

再次查看（需要reboot重启）

[root@localhost ~]# sestatus

（3）防火墙

关闭

[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# systemctl mask firewalld

（4）安装java

[root@localhost ~]# yum install -y java-1.8.0-openjdk-devel.x86_64

查看

[root@localhost ~]# jps

 （5）修改主机名

[root@localhost ~]# hostnamectl set-hostname node05
[root@localhost ~]# bash

（6）添加免密登录

[root@hadoop ~]# cd /root/.ssh/
[root@hadoop .ssh]# ls
authorized_keys  id_rsa  id_rsa.pub  known_hosts
[root@hadoop .ssh]# ssh-copy-id -i id_rsa.pub 192.168.204.55

验证：

[root@hadoop .ssh]# ssh 192.168.204.55

 （7）域名主机名(hadoop节点)

[root@hadoop ~]# vim /etc/hosts
……
192.168.205.50 hadoop
192.168.205.51 node01
192.168.205.52 node02
192.168.205.53 node03
192.168.204.54 node04
192.168.204.55 node05

（8）同步域名配置文件

[root@hadoop ~]# rsync -av /etc/hosts node01:/etc/
sending incremental file list
hosts

sent 382 bytes  received 41 bytes  282.00 bytes/sec
total size is 291  speedup is 0.69
[root@hadoop ~]# rsync -av /etc/hosts node02:/etc/
sending incremental file list
hosts

sent 382 bytes  received 41 bytes  282.00 bytes/sec
total size is 291  speedup is 0.69
[root@hadoop ~]# rsync -av /etc/hosts node03:/etc/
sending incremental file list
hosts

sent 382 bytes  received 41 bytes  846.00 bytes/sec
total size is 291  speedup is 0.69
[root@hadoop ~]# rsync -av /etc/hosts node05:/etc/
Warning: Permanently added 'node05' (ECDSA) to the list of known hosts.
sending incremental file list
hosts

sent 382 bytes  received 41 bytes  846.00 bytes/sec
total size is 291  speedup is 0.69

（9）同步Hadoop文件

[root@hadoop ~]# rsync -aXSH --delete /usr/local/hadoop node05:/usr/local/

(10) 清除日志（node05节点）

[root@node05 ~]# cd /usr/local/hadoop/
[root@node05 hadoop]# ls
bin  etc  include  lib  libexec  LICENSE.txt  logs  NOTICE.txt  README.txt  sbin  share
[root@node05 hadoop]# cd logs/
[root@node05 logs]# ls
hadoop-root-balancer-hadoop.log  hadoop-root-namenode-hadoop.out           hadoop-root-secondarynamenode-hadoop.out    yarn-root-resourcemanager-hadoop.log
hadoop-root-balancer-hadoop.out  hadoop-root-namenode-hadoop.out.1         hadoop-root-secondarynamenode-hadoop.out.1  yarn-root-resourcemanager-hadoop.out
hadoop-root-namenode-hadoop.log  hadoop-root-secondarynamenode-hadoop.log  SecurityAuth-root.audit
[root@node05 logs]# rm -f *
[root@node05 logs]# ls
[root@node05 logs]#

（11）启动服务 （node05节点）

[root@node05 hadoop]# ./sbin/yarn-daemon.sh start nodemanager

查看jps 出现新角色

(15) 验证 （hadoop节点）

服务已互通

[root@hadoop hadoop]#  ./bin/yarn node -list
24/03/14 18:07:06 INFO client.RMProxy: Connecting to ResourceManager at hadoop/192.168.204.50:8032
Total Nodes:4
         Node-Id             Node-State Node-Http-Address       Number-of-Running-Containers
    node01:40551                RUNNING       node01:8042                                  0
    node05:39920                RUNNING       node05:8042                                  0
    node02:46073                RUNNING       node02:8042                                  0
    node03:40601                RUNNING       node03:8042                                  0

3.Yarn 节点缩容

（1）删除节点 （node05节点）

[root@node05 hadoop]# ./sbin/yarn-daemon.sh stop nodemanager

查看jps

（2）验证 （hadoop节点）

这时node05节点还在(因为存在检测超时)

[root@hadoop hadoop]#  ./bin/yarn node -list

(3) 停止服务（hadoop节点）

[root@hadoop hadoop]# ./sbin/yarn-daemon.sh stop resourcemanager

（4）启动服务（hadoop节点）

[root@hadoop hadoop]# ./sbin/yarn-daemon.sh start resourcemanager

（5）验证 （hadoop节点）

这时暂无节点，需要等待30秒-1分钟

[root@hadoop hadoop]#  ./bin/yarn node -list

（6）再次验证 （hadoop节点）

node05节点已移除

[root@hadoop hadoop]#  ./bin/yarn node -list

二、问题

1.yarn启动服务报错

（1）报错

错误: 找不到或无法加载主类 nodemanager

（2）原因分析

命令错误。

（3）解决方法

修改命令，hadoop-daemon.sh 改为 yarn-daemon.sh

[root@node05 hadoop]# ./sbin/yarn-daemon.sh start nodemanager