HDFS部署体验
目录 简单说明 重要的配置参数及配置选择 部署实践，参数配置修改记录 local machine, NameNode local machine, DataNode 192.168.1.101, DataNode 启动HDFS cluster 启动验证 hdfs shell创建文件 问题与解决 关闭HDFS cluster 结论 简单说明 下载hadoop distribution 有三个包： （区别是啥？） hadoop-x.y.z-site.tar.gz hadoop-x.y.z-src.tar.gz hadoop-x.y.z.tar.gz hadoop由不同的组件组成，不同组件有不同的daemon，每个daemon是独立的java process；配置daemon的启动参数，是通过环境变量实现 HDFS 在 etc/hadoop/hadoop-evn.sh 中配置 NameNode daemon: HDFS_NAMENODE_OPTS DataNode daemon: HDFS_DATANODE_OPTS Secondary NameNode daemon: HDFS_SECONDARYNAMENODE_OPTS YARN 在 etc/hadoop/yarn-evn.sh 中配置 ResourceManager daemon: YARN_RESOURCEMANAGER_OPTS NodeManager daemon: YARN_NODEMANAGER_OPTS WebAppProxy daemon: YARN_PROXYSERVER_OPTS MapReduce 在 etc/hadoop/mapred-evn.sh 中配置 MAP Reduce Job History Server daemon: MAPRED_HISTORYSERVER_OPTS hadoop全局配置，在系统文件（~/.bashrc）中配置 HADOOP_HOME: hadoop distribution的家目录，至少要配置 HADOOP_PID_DIR HADOOP_LOG_DIR HADOOP_HEAPSIZE_MAX 重要的配置参数及配置选择 所有节点都要配置 etc/hadoop/core-site.xml 示例配置位置：./share/doc/hadoop/hadoop-project-dist/hadoop-common/core-default.xml fs.defaultFS 配置HDFS中NameNode的URI io.file.buffer.size NameNode节点配置 etc/hadoop/hdfs-site.xml 示例配置位置：./share/doc/hadoop/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml dfs.namenode.name.dir dfs.hosts / dfs.hosts/excluded dfs.blocksize dfs.namenode.handler.count DataNode节点配置 etc/hadoop/hdfs-site.xml dfs.datanode.data.dir 部署实践，参数配置修改记录 local machine, NameNode system环境变量 export HADOOP_HOME="/home/jng/installed/hadoop/hadoop-3.2.0" export HADOOP_PID_DIR="/home/jng/installed/hadoop/hadoop_pid_dir" export HADOOP_LOG_DIR="/home/jng/installed/hadoop/hadoop_log_dir" etc/hadoop/core-size.xml fs.defaultFS <property> fs.defaultFShdfs://195.90.3.212:9988/The name of the default file system. A URI whosescheme and authority determine the FileSystem implementation. Theuri's scheme determines the config property (fs.SCHEME.impl) namingthe FileSystem implementation class. The uri's authority is used todetermine the host, port, etc. for a filesystem. </property> io.file.buffer.size <property> io.file.buffer.size4096The size of buffer for use in sequence files.The size of this buffer should probably be a multiple of hardwarepage size (4096 on Intel x86), and it determines how much data isbuffered during read and write operations. </property> etc/hadoop/hdfs-site.xml dfs.namenode.name.dir <property> <name>dfs.namenode.name.dir</name> <value>file:///home/jng/installed/hadoop/dfs_namenode_name_dir</value> <description>Determines where on the local filesystem the DFS name node should store the name table(fsimage). If this is a comma-delimited listof directories then the name table is replicated in all of thedirectories, for redundancy. </property> local machine, DataNode etc/hadoop/hdfs-site.xml dfs.datanode.data.dir <property> dfs.datanode.data.dirfile:///home/jng/installed/hadoop/dfs_datanode_data_dirDetermines where on the local filesystem an DFS data nodeshould store its blocks. If this is a comma-delimitedlist of directories, then data will be stored in all nameddirectories, typically on different devices. The directories should be taggedwith corresponding storage types ([SSD]/[DISK]/[ARCHIVE]/[RAM_DISK]) for HDFSstorage policies. The default storage type will be DISK if the directory doesnot have a storage type tagged explicitly. Directories that do not exist willbe created if local filesystem permission allows. </property> 192.168.1.101, DataNode system环境变量 export HADOOP_HOME="/home/mhb/installed/hadoop/hadoop-3.2.0" export HADOOP_PID_DIR="/home/mhb/installed/hadoop/hadoop_pid_dir" export HADOOP_LOG_DIR="/home/mhb/installed/hadoop/hadoop_log_dir" etc/hadoop/core-site.html fs.defaultFS <property> fs.defaultFShdfs://195.90.3.212:9988/The name of the default file system. A URI whosescheme and authority determine the FileSystem implementation. Theuri's scheme determines the config property (fs.SCHEME.impl) namingthe FileSystem implementation class. The uri's authority is used todetermine the host, port, etc. for a filesystem. </property> io.file.buffer.size <property> io.file.buffer.size4096The size of buffer for use in sequence files.The size of this buffer should probably be a multiple of hardwarepage size (4096 on Intel x86), and it determines how much data isbuffered during read and write operations. </property> etc/hadoop/hdfs-site.xml dfs.datanode.data.dir <property> dfs.datanode.data.dirfile:///home/mhb/installed/hadoop/dfs_datanode_data_dirDetermines where on the local filesystem an DFS data nodeshould store its blocks. If this is a comma-delimitedlist of directories, then data will be stored in all nameddirectories, typically on different devices. The directories should be taggedwith corresponding storage types ([SSD]/[DISK]/[ARCHIVE]/[RAM_DISK]) for HDFSstorage policies. The default storage type will be DISK if the directory doesnot have a storage type tagged explicitly. Directories that do not exist willbe created if local filesystem permission allows. </property> 启动HDFS cluster 首次启动HDFS cluster必须进行格式化 # 在namenode设备上执行（？？） $ $HADOOP_HOME/bin/hdfs namenode -format <cluster_name> 启动NameNode # 在namenode设备上执行 $ $HADOOP_HOME/bin/hdfs --daemon start namenode 启动DataNode $ $HADOOP_HOME/bin/hdfs --daemon start datanode 可选一键启动 # 前提是同时满足: 1)etc/hadoop/workers文件被正确配置;2)NameNode设备与DataNode设备间无密码ssh访问已经配置完毕 $ $HADOOP_HOME/sbin/start-dfs.sh 启动验证 查看NameNode的web ui: http://ip:port default port is: 9870 查看DataNode的web ui: http://ip:port default port is: 9864 hdfs shell创建文件 从本地copy大尺寸文件到hdfs中，查看namenode、datanode的数据存储文件夹大小变化 copy文件前 local machine as NameNode的dfs.namenode.name.dir路径 [j@j dfs_namenode_name_dir]$ pwd /home/jng/installed/hadoop/dfs_namenode_name_dir [j@j dfs_namenode_name_dir]$ du -hs 2.1M . [j@j dfs_namenode_name_dir]$ local machine as DataNode的dfs.datanode.data.dir路径 [j@j dfs_datanode_data_dir]$ pwd /home/jng/installed/hadoop/dfs_datanode_data_dir [j@j dfs_datanode_data_dir]$ du -hs 44K . [j@j dfs_datanode_data_dir]$ 192.168.1.101 DataNode的dfs.datanode.data.dir路径 m@m:~/installed/hadoop/dfs_datanode_data_dir$ pwd /home/mhb/installed/hadoop/dfs_datanode_data_dir m@m:~/installed/hadoop/dfs_datanode_data_dir$ du -hs 44K . m@m:~/installed/hadoop/dfs_datanode_data_dir$ copy文件 # 在NameNode上操作 [j@j hadoop-3.2.0]$ pwd /home/jng/installed/hadoop/hadoop-3.2.0 [j@j hadoop-3.2.0]$ ls -lh ~/software/hadoop/hadoop-3.2.0.tar.gz -rw-r--r-- 1 jng jng 330M 2月 25 14:21 /home/jng/software/hadoop/hadoop-3.2.0.tar.gz [j@j hadoop-3.2.0]$ ./bin/hdfs dfs -moveFromLocal ~/software/hadoop/hadoop-3.2.0.tar.gz /tmp/ copy文件后 local machine as NameNode的dfs.namenode.name.dir路径 [j@j dfs_namenode_name_dir]$ pwd /home/jng/installed/hadoop/dfs_namenode_name_dir [j@j dfs_namenode_name_dir]$ du -hs 2.1M . [j@j dfs_namenode_name_dir]$ local machine as DataNode的dfs.datanode.data.dir路径 [j@j dfs_datanode_data_dir]$ pwd /home/jng/installed/hadoop/dfs_datanode_data_dir [j@j dfs_datanode_data_dir]$ du -hs 333M . [j@j dfs_datanode_data_dir]$ 192.168.1.101 as DataNode的dfs.dataanode.data.dir路径 m@m:~/installed/hadoop/dfs_datanode_data_dir$ pwd /home/mhb/installed/hadoop/dfs_datanode_data_dir m@m:~/installed/hadoop/dfs_datanode_data_dir$ du -hs 333M . m@m:~/installed/hadoop/dfs_datanode_data_dir$ 问题与解决 NameNode web UI 上查看 namenode-log 可能发现 WARN 形如：“WARN org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager: Unresolved datanode registration: hostname cannot be resolved (ip=192.168.1.101, hostname=192.168.1.101)“ ref: <https://blog.csdn.net/qqpy789/article/details/78189335> 修改文件 etc/hadoop/hdfs-site.xml 配置 dfs.namenode.datanode.registration.ip-hostname-check 取值为false <property> <name>dfs.namenode.datanode.registration.ip-hostname-check</name> <value>false</value> <description> If true (the default), then the namenode requires that a connectingdatanode's address must be resolved to a hostname. If necessary, a reverseDNS lookup is performed. All attempts to register a datanode from anunresolvable address are rejected. It is recommended that this setting be left on to prevent accidentalregistration of datanodes listed by hostname in the excludes file during aDNS outage. Only set this to false in environments where there is noinfrastructure to support reverse DNS lookup. </description> </property> 关闭HDFS cluster 关闭NameNode # 在NameNode设备上执行 $ $HADOOP_HOME/bin/hdfs --daemon stop namenode 关闭DataNode $ $HADOOP_HOME/bin/hdfs --daemon stop datanode 结论 HDFS可以独立与YARN存在并运行 即，不启动YARN,HDFS也能正常运行，至少通过HDFS shell是这样 HDFS的NameNode设备上可以同时运行一个DataNode
