Hadoop大数据应用：Yarn 节点实现扩容与缩容_hadoop在线扩容和缩容

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

---

  一、实验

1.环境

（1）主机

表1  主机

（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