目录
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 SecondaryNameNode | hadoop | 2.7.7 | 192.168.204.50 | |
| node01 | DataNode | hadoop | 2.7.7 | 192.168.204.51 | |
| node02 | DataNode | hadoop | 2.7.7 | 192.168.204.52 | |
| node03 | DataNode | hadoop | 2.7.7 | 192.168.204.53 |
（2）安全机制
查看
[root@localhost ~]# sestatus
关闭
[root@localhost ~]# vim /etc/selinux/config
……
SELINUX=disabled
……
再次查看
[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
hadoop
node01
node02
node03
（5）域名主机名
[root@localhost ~]# vim /etc/hosts
……
192.168.205.50 hadoop
192.168.205.51 node01
192.168.205.52 node02
192.168.205.53 node03
（6）修改主机名
[root@localhost ~]# hostnamectl set-hostname 主机名
[root@localhost ~]# bash
（7）hadoop节点创建密钥
[root@hadoop ~]# mkdir /root/.ssh
[root@hadoop ~]# cd /root/.ssh/
[root@hadoop .ssh]# ssh-keygen -t rsa -b 2048 -N ''
（8）添加免密登录
[root@hadoop .ssh]# ssh-copy-id -i id_rsa.pub hadoop
[root@hadoop .ssh]# ssh-copy-id -i id_rsa.pub node01
[root@hadoop .ssh]# ssh-copy-id -i id_rsa.pub node02
[root@hadoop .ssh]# ssh-copy-id -i id_rsa.pub node03
2.Linux 部署 HDFS 分布式集群
（1）官网
https://hadoop.apache.org/查看版本
https://archive.apache.org/dist/hadoop/common/（2）下载
wget https://archive.apache.org/dist/hadoop/common/hadoop-2.7.7/hadoop-2.7.7.tar.gz
(3) 解压
tar -zxf hadoop-2.7.7.tar.gz
（3）移动
mv hadoop-2.7.7 /usr/local/hadoop
（4）更改权限
chown -R root.root hadoop
（5）验证版本
（需要修改环境配置文件hadoop-env.sh 申明JAVA安装路径和hadoop配置文件路径）
修改配置文件
[root@hadoop hadoop]# vim hadoop-env.sh
验证
[root@hadoop hadoop]# ./bin/hadoop version
（6）修改节点配置文件
[root@hadoop hadoop]# vim slaves
修改前：
修改后：
node01
node02
node03
（7）查看官方文档
https://hadoop.apache.org/docs/指定版本
https://hadoop.apache.org/docs/r2.7.7/
查看核心配置文件
https://hadoop.apache.org/docs/r2.7.7/hadoop-project-dist/hadoop-common/core-default.xml文件系统配置参数：
数据目录配置参数：
（8）修改核心配置文件
[root@hadoop hadoop]# vim core-site.xml
修改前：
修改后：
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://hadoop:9000</value>
<description>hdfs file system</description>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/var/hadoop</value>
</property>
</configuration>
（9）查看HDFS配置文件
https://hadoop.apache.org/docs/r2.7.7/hadoop-project-dist/hadoop-hdfs/hdfs-default.xmlnamenode:
副本数量：
（10）修改HDFS配置文件
[root@hadoop hadoop]# vim hdfs-site.xml
修改前：
修改后：
<configuration>
<property>
<name>dfs.namenode.http-address</name>
<value>hadoop:50070</value>
<name>dfs.namenode.secondary.http-address</name>
<value>hadoop:50090</value>
<name>dfs.replication</name>
<value>2</value>
</property>
</configuration>
(11) 查看同步
[root@hadoop ~]# rpm -q rsync
同步
[root@hadoop ~]# rsync -aXSH --delete /usr/local/hadoop node01:/usr/local/
[root@hadoop ~]# rsync -aXSH --delete /usr/local/hadoop node02:/usr/local/
[root@hadoop ~]# rsync -aXSH --delete /usr/local/hadoop node03:/usr/local/
（12）初始化hdfs
[root@hadoop ~]# mkdir /var/hadoop
（13）查看命令
[root@hadoop hadoop]# ./bin/hdfs
Usage: hdfs [--config confdir] [--loglevel loglevel] COMMAND
where COMMAND is one of:
dfs run a filesystem command on the file systems supported in Hadoop.
classpath prints the classpath
namenode -format format the DFS filesystem
secondarynamenode run the DFS secondary namenode
namenode run the DFS namenode
journalnode run the DFS journalnode
zkfc run the ZK Failover Controller daemon
datanode run a DFS datanode
dfsadmin run a DFS admin client
haadmin run a DFS HA admin client
fsck run a DFS filesystem checking utility
balancer run a cluster balancing utility
jmxget get JMX exported values from NameNode or DataNode.
mover run a utility to move block replicas across
storage types
oiv apply the offline fsimage viewer to an fsimage
oiv_legacy apply the offline fsimage viewer to an legacy fsimage
oev apply the offline edits viewer to an edits file
fetchdt fetch a delegation token from the NameNode
getconf get config values from configuration
groups get the groups which users belong to
snapshotDiff diff two snapshots of a directory or diff the
current directory contents with a snapshot
lsSnapshottableDir list all snapshottable dirs owned by the current user
Use -help to see options
portmap run a portmap service
nfs3 run an NFS version 3 gateway
cacheadmin configure the HDFS cache
crypto configure HDFS encryption zones
storagepolicies list/get/set block storage policies
version print the version
Most commands print help when invoked w/o parameters.
（14）格式化hdfs
[root@hadoop hadoop]# ./bin/hdfs namenode -format
查看目录
[root@hadoop hadoop]# cd /var/hadoop/
[root@hadoop hadoop]# tree .
.
└── dfs
└── name
└── current
├── fsimage_0000000000000000000
├── fsimage_0000000000000000000.md5
├── seen_txid
└── VERSION
3 directories, 4 files
(15) 启动集群
查看目录
[root@hadoop hadoop]# cd ~
[root@hadoop ~]# cd /usr/local/hadoop/
[root@hadoop hadoop]# ls
启动
[root@hadoop hadoop]# ./sbin/start-dfs.sh
查看日志（新生成logs目录）
[root@hadoop hadoop]# cd logs/ ; ll
查看jps
[root@hadoop hadoop]# jps
datanode节点查看（node01）
datanode节点查看（node02）
datanode节点查看（node03）
(16)查看命令
[root@hadoop hadoop]# ./bin/hdfs dfsadmin
Usage: hdfs dfsadmin
Note: Administrative commands can only be run as the HDFS superuser.
[-report [-live] [-dead] [-decommissioning]]
[-safemode <enter | leave | get | wait>]
[-saveNamespace]
[-rollEdits]
[-restoreFailedStorage true|false|check]
[-refreshNodes]
[-setQuota <quota> <dirname>...<dirname>]
[-clrQuota <dirname>...<dirname>]
[-setSpaceQuota <quota> [-storageType <storagetype>] <dirname>...<dirname>]
[-clrSpaceQuota [-storageType <storagetype>] <dirname>...<dirname>]
[-finalizeUpgrade]
[-rollingUpgrade [<query|prepare|finalize>]]
[-refreshServiceAcl]
[-refreshUserToGroupsMappings]
[-refreshSuperUserGroupsConfiguration]
[-refreshCallQueue]
[-refresh <host:ipc_port> <key> [arg1..argn]
[-reconfig <datanode|...> <host:ipc_port> <start|status>]
[-printTopology]
[-refreshNamenodes datanode_host:ipc_port]
[-deleteBlockPool datanode_host:ipc_port blockpoolId [force]]
[-setBalancerBandwidth <bandwidth in bytes per second>]
[-fetchImage <local directory>]
[-allowSnapshot <snapshotDir>]
[-disallowSnapshot <snapshotDir>]
[-shutdownDatanode <datanode_host:ipc_port> [upgrade]]
[-getDatanodeInfo <datanode_host:ipc_port>]
[-metasave filename]
[-triggerBlockReport [-incremental] <datanode_host:ipc_port>]
[-help [cmd]]
Generic options supported are
-conf <configuration file> specify an application configuration file
-D <property=value> use value for given property
-fs <local|namenode:port> specify a namenode
-jt <local|resourcemanager:port> specify a ResourceManager
-files <comma separated list of files> specify comma separated files to be copied to the map reduce cluster
-libjars <comma separated list of jars> specify comma separated jar files to include in the classpath.
-archives <comma separated list of archives> specify comma separated archives to be unarchived on the compute machines.
The general command line syntax is
（17）验证集群
查看报告，发现3个节点
[root@hadoop hadoop]# ./bin/hdfs dfsadmin -report
Configured Capacity: 616594919424 (574.25 GB)
Present Capacity: 598915952640 (557.78 GB)
DFS Remaining: 598915915776 (557.78 GB)
DFS Used: 36864 (36 KB)
DFS Used%: 0.00%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0
Missing blocks (with replication factor 1): 0
-------------------------------------------------
Live datanodes (3):
Name: 192.168.204.53:50010 (node03)
Hostname: node03
Decommission Status : Normal
Configured Capacity: 205531639808 (191.42 GB)
DFS Used: 12288 (12 KB)
Non DFS Used: 5620584448 (5.23 GB)
DFS Remaining: 199911043072 (186.18 GB)
DFS Used%: 0.00%
DFS Remaining%: 97.27%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Mar 14 10:30:18 CST 2024
Name: 192.168.204.51:50010 (node01)
Hostname: node01
Decommission Status : Normal
Configured Capacity: 205531639808 (191.42 GB)
DFS Used: 12288 (12 KB)
Non DFS Used: 6028849152 (5.61 GB)
DFS Remaining: 199502778368 (185.80 GB)
DFS Used%: 0.00%
DFS Remaining%: 97.07%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Mar 14 10:30:18 CST 2024
Name: 192.168.204.52:50010 (node02)
Hostname: node02
Decommission Status : Normal
Configured Capacity: 205531639808 (191.42 GB)
DFS Used: 12288 (12 KB)
Non DFS Used: 6029533184 (5.62 GB)
DFS Remaining: 199502094336 (185.80 GB)
DFS Used%: 0.00%
DFS Remaining%: 97.07%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Mar 14 10:30:18 CST 2024
（18）web页面验证
http://192.168.204.50:50070/
http://192.168.204.50:50090/
http://192.168.204.51:50075/
(19)访问系统
目前为空
3.Linux 使用 HDFS 文件系统
（1）查看命令
[root@hadoop hadoop]# ./bin/hadoop
Usage: hadoop [--config confdir] [COMMAND | CLASSNAME]
CLASSNAME run the class named CLASSNAME
or
where COMMAND is one of:
fs run a generic filesystem user client
version print the version
jar <jar> run a jar file
note: please use "yarn jar" to launch
YARN applications, not this command.
checknative [-a|-h] check native hadoop and compression libraries availability
distcp <srcurl> <desturl> copy file or directories recursively
archive -archiveName NAME -p <parent path> <src>* <dest> create a hadoop archive
classpath prints the class path needed to get the
credential interact with credential providers
Hadoop jar and the required libraries
daemonlog get/set the log level for each daemon
trace view and modify Hadoop tracing settings
Most commands print help when invoked w/o parameters.
[root@hadoop hadoop]# ./bin/hadoop fs
Usage: hadoop fs [generic options]
[-appendToFile <localsrc> ... <dst>]
[-cat [-ignoreCrc] <src> ...]
[-checksum <src> ...]
[-chgrp [-R] GROUP PATH...]
[-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
[-chown [-R] [OWNER][:[GROUP]] PATH...]
[-copyFromLocal [-f] [-p] [-l] <localsrc> ... <dst>]
[-copyToLocal [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
[-count [-q] [-h] <path> ...]
[-cp [-f] [-p | -p[topax]] <src> ... <dst>]
[-createSnapshot <snapshotDir> [<snapshotName>]]
[-deleteSnapshot <snapshotDir> <snapshotName>]
[-df [-h] [<path> ...]]
[-du [-s] [-h] <path> ...]
[-expunge]
[-find <path> ... <expression> ...]
[-get [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
[-getfacl [-R] <path>]
[-getfattr [-R] {-n name | -d} [-e en] <path>]
[-getmerge [-nl] <src> <localdst>]
[-help [cmd ...]]
[-ls [-d] [-h] [-R] [<path> ...]]
[-mkdir [-p] <path> ...]
[-moveFromLocal <localsrc> ... <dst>]
[-moveToLocal <src> <localdst>]
[-mv <src> ... <dst>]
[-put [-f] [-p] [-l] <localsrc> ... <dst>]
[-renameSnapshot <snapshotDir> <oldName> <newName>]
[-rm [-f] [-r|-R] [-skipTrash] <src> ...]
[-rmdir [--ignore-fail-on-non-empty] <dir> ...]
[-setfacl [-R] [{-b|-k} {-m|-x <acl_spec>} <path>]|[--set <acl_spec> <path>]]
[-setfattr {-n name [-v value] | -x name} <path>]
[-setrep [-R] [-w] <rep> <path> ...]
[-stat [format] <path> ...]
[-tail [-f] <file>]
[-test -[defsz] <path>]
[-text [-ignoreCrc] <src> ...]
[-touchz <path> ...]
[-truncate [-w] <length> <path> ...]
[-usage [cmd ...]]
Generic options supported are
-conf <configuration file> specify an application configuration file
-D <property=value> use value for given property
-fs <local|namenode:port> specify a namenode
-jt <local|resourcemanager:port> specify a ResourceManager
-files <comma separated list of files> specify comma separated files to be copied to the map reduce cluster
-libjars <comma separated list of jars> specify comma separated jar files to include in the classpath.
-archives <comma separated list of archives> specify comma separated archives to be unarchived on the compute machines.
The general command line syntax is
bin/hadoop command [genericOptions] [commandOptions]
（2）查看文件目录
[root@hadoop hadoop]# ./bin/hadoop fs -ls /
（3）创建文件夹
[root@hadoop hadoop]# ./bin/hadoop fs -mkdir /devops
查看
查看web
（4）上传文件
[root@hadoop hadoop]# ./bin/hadoop fs -put *.txt /devops/
查看
[root@hadoop hadoop]# ./bin/hadoop fs -ls /devops/
查看web
Permission Owner Group Size Last Modified Replication Block Size Name
-rw-r--r-- root supergroup 84.4 KB 2024/3/14 11:05:33 2 128 MB LICENSE.txt
-rw-r--r-- root supergroup 14.63 KB 2024/3/14 11:05:34 2 128 MB NOTICE.txt
-rw-r--r-- root supergroup 1.33 KB 2024/3/14 11:05:34 2 128 MB README.txt
下载
（5）创建文件
[root@hadoop hadoop]# ./bin/hadoop fs -touchz /tfile
查看
[root@hadoop hadoop]# ./bin/hadoop fs -ls /
（5）下载文件
[root@hadoop hadoop]# ./bin/hadoop fs -get /tfile /tmp/
查看
[root@hadoop hadoop]# ls -l /tmp/ | grep tfile
查看web
(6) 查看命令比较
之前的设置
所以查看功能相同
[root@hadoop hadoop]# ./bin/hadoop fs -ls /
[root@hadoop hadoop]# ./bin/hadoop fs -ls hdfs://hadoop:9000/
另外官网默认是file ，使用的是本地文件目录
[root@hadoop hadoop]# ./bin/hadoop fs -ls file:///
二、问题
1.ssh-copy-id 报错
（1）报错
/usr/bin/ssh-copy-id: ERROR: ssh: connect to host hadoop port 22: Connection refused
（2）原因分析
主机解析错误。
（3）解决方法
修改前：
修改后：
成功：
2. 如何禁用ssh key 检测
（1）修改配置文件
[root@hadoop .ssh]# vim /etc/ssh/ssh_config
添加配置
StrictHostKeyChecking no
成功：
3.HDFS有哪些配置文件
（1）配置文件
1）环境配置文件
hadoop-env.sh
2)核心配置文件
core-site.xml
3)HDFS配置文件
hdfs-site.xml
4)节点配置文件
slaves4.hadoop查看版本报错
(1) 报错
（2）原因分析
未申明JAVA环境。
（3）解决方法
申明JAVA环境。
查看
rpm -ql java-1.8.0-openjdk
确定JAVA环境
/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.402.b06-1.el7_9.x86_64/jre确定配置路径
/usr/local/hadoop/etc/hadoop修改配置文件
[root@hadoop hadoop]# vim hadoop-env.sh
修改前：
修改后：
成功：
[root@hadoop hadoop]# ./bin/hadoop version
5.启动集群报错
（1）报错
（2）原因分析
ssh-copy-id 未对本地主机验证。
（3）解决方法
ssh-copy-id 对本地主机验证。
[root@hadoop hadoop]# ssh-copy-id hadoop
如继续报错
需要停止Hadoop HDFS守护进程NameNode、SecondaryNameNode和DataNode
[root@hadoop hadoop]# ./sbin/stop-dfs.sh
再次启动
6.hadoop 的启动和停止命令
（1）命令
sbin/start-all.sh 启动所有的Hadoop守护进程。包括NameNode、 Secondary NameNode、DataNode、ResourceManager、NodeManager
sbin/stop-all.sh 停止所有的Hadoop守护进程。包括NameNode、 Secondary NameNode、DataNode、ResourceManager、NodeManager
sbin/start-dfs.sh 启动Hadoop HDFS守护进程NameNode、SecondaryNameNode、DataNode
sbin/stop-dfs.sh 停止Hadoop HDFS守护进程NameNode、SecondaryNameNode和DataNode
sbin/hadoop-daemons.sh start namenode 单独启动NameNode守护进程
sbin/hadoop-daemons.sh stop namenode 单独停止NameNode守护进程
sbin/hadoop-daemons.sh start datanode 单独启动DataNode守护进程
sbin/hadoop-daemons.sh stop datanode 单独停止DataNode守护进程
sbin/hadoop-daemons.sh start secondarynamenode 单独启动SecondaryNameNode守护进程
sbin/hadoop-daemons.sh stop secondarynamenode 单独停止SecondaryNameNode守护进程
sbin/start-yarn.sh 启动ResourceManager、NodeManager
sbin/stop-yarn.sh 停止ResourceManager、NodeManager
sbin/yarn-daemon.sh start resourcemanager 单独启动ResourceManager
sbin/yarn-daemons.sh start nodemanager 单独启动NodeManager
sbin/yarn-daemon.sh stop resourcemanager 单独停止ResourceManager
sbin/yarn-daemons.sh stopnodemanager 单独停止NodeManager
sbin/mr-jobhistory-daemon.sh start historyserver 手动启动jobhistory
sbin/mr-jobhistory-daemon.sh stop historyserver 手动停止jobhistory7.上传文件报错
（1）报错
（2）原因分析
命令错误
（3）解决方法
使用正确命令
[root@hadoop hadoop]# ./bin/hadoop fs -put *.txt /devops/
8.HDFS 使用命令
（1）命令
ls 查看文件或目录
cat 查看文件内容
put 上传
get 下载