HDFS：分布式文件系统
HDFS集群模式
| 节点 | IP | 角色 |
| node1 | 192.168.55.128 | NameNode，DataNode |
| node2 | 192.168.55.129 | SecondaryNameNode，DataNode |
| node3 | 192.168.55.130 | DataNode |
Hadoop环境变量
[root@node1 ~]# vi /etc/profile.d/custom.sh
#Hadoop pathexport HADOOP_HOME=/opt/hadoop-2.7.3export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin
[root@node1 ~]# source /etc/profile.d/custom.sh
同理在node2和node3也要进行类似的环境变量配置。
准备工作
由于前面在node1上部署了Hadoop单机模式，需要停止Hadoop所有服务并清除数据目录。顺便检验一下设置的Hadoop环境变量。
清除Hadoop数据目录
[root@node1 ~]# rm -rf /tmp/hadoop-root/
core-site.xml
[root@node1 ~]# cd /opt/hadoop-2.7.3/etc/hadoop/[root@node1 hadoop]# vi core-site.xml
core-site.xml文件内容如下：
fs.defaultFS hdfs://node1:9000 hadoop.tmp.dir /var/data/hadoop io.file.buffer.size 65536
hdfs-site.xm
[root@node1 hadoop]# vi hdfs-site.xml
hdfs-site.xml文件内容如下：
dfs.replication 3 dfs.namenode.secondary.http-address node2:50090 dfs.namenode.secondary.https-address node2:50091
slaves
编辑slaves文件
[root@node1 hadoop]# vi slaves
slaves文件内容设置为：
分发文件
将Hadoop软件包复制到node2和node3节点上
[root@node1 ~]# scp -r /opt/hadoop-2.7.3/ node2:/opt
[root@node1 ~]# scp -r /opt/hadoop-2.7.3/ node3:/opt
将环境变量文件复制到node2和node3节点上
[root@node2 ~]# source /etc/profile.d/custom.sh
[root@node3 ~]# source /etc/profile.d/custom.sh
NameNode格式化
[root@node1 ~]# hdfs namenode -format
18/11/22 22:09:59 INFO namenode.NameNode: registered UNIX signal handlers for [TERM, HUP, INT]18/11/22 22:09:59 INFO namenode.NameNode: createNameNode [-format]Formatting using clusterid: CID-1435a0cf-33c1-4c5e-9473-b88769f60dcd18/11/22 22:10:03 INFO namenode.FSNamesystem: No KeyProvider found.18/11/22 22:10:03 INFO namenode.FSNamesystem: fsLock is fair:true18/11/22 22:10:03 INFO blockmanagement.DatanodeManager: dfs.block.invalidate.limit=100018/11/22 22:10:03 INFO blockmanagement.DatanodeManager: dfs.namenode.datanode.registration.ip-hostname-check=true18/11/22 22:10:03 INFO blockmanagement.BlockManager: dfs.namenode.startup.delay.block.deletion.sec is set to 000:00:00:00.00018/11/22 22:10:03 INFO blockmanagement.BlockManager: The block deletion will start around 2018 Nov 22 22:10:0318/11/22 22:10:03 INFO util.GSet: Computing capacity for map BlocksMap18/11/22 22:10:03 INFO util.GSet: VM type = 64-bit18/11/22 22:10:04 INFO util.GSet: 2.0% max memory 966.7 MB = 19.3 MB18/11/22 22:10:04 INFO util.GSet: capacity = 2^21 = 2097152 entries18/11/22 22:10:04 INFO blockmanagement.BlockManager: dfs.block.access.token.enable=false18/11/22 22:10:04 INFO blockmanagement.BlockManager: defaultReplication = 318/11/22 22:10:04 INFO blockmanagement.BlockManager: maxReplication = 51218/11/22 22:10:04 INFO blockmanagement.BlockManager: minReplication = 118/11/22 22:10:04 INFO blockmanagement.BlockManager: maxReplicationStreams = 218/11/22 22:10:04 INFO blockmanagement.BlockManager: replicationRecheckInterval = 300018/11/22 22:10:04 INFO blockmanagement.BlockManager: encryptDataTransfer = false18/11/22 22:10:04 INFO blockmanagement.BlockManager: maxNumBlocksToLog = 100018/11/22 22:10:04 INFO namenode.FSNamesystem: fsOwner = root (auth:SIMPLE)18/11/22 22:10:04 INFO namenode.FSNamesystem: supergroup = supergroup18/11/22 22:10:04 INFO namenode.FSNamesystem: isPermissionEnabled = true18/11/22 22:10:04 INFO namenode.FSNamesystem: HA Enabled: false18/11/22 22:10:04 INFO namenode.FSNamesystem: Append Enabled: true18/11/22 22:10:07 INFO util.GSet: Computing capacity for map INodeMap18/11/22 22:10:07 INFO util.GSet: VM type = 64-bit18/11/22 22:10:07 INFO util.GSet: 1.0% max memory 966.7 MB = 9.7 MB18/11/22 22:10:07 INFO util.GSet: capacity = 2^20 = 1048576 entries18/11/22 22:10:07 INFO namenode.FSDirectory: ACLs enabled? false18/11/22 22:10:07 INFO namenode.FSDirectory: XAttrs enabled? true18/11/22 22:10:07 INFO namenode.FSDirectory: Maximum size of an xattr: 1638418/11/22 22:10:07 INFO namenode.NameNode: Caching file names occuring more than 10 times18/11/22 22:10:07 INFO util.GSet: Computing capacity for map cachedBlocks18/11/22 22:10:07 INFO util.GSet: VM type = 64-bit18/11/22 22:10:07 INFO util.GSet: 0.25% max memory 966.7 MB = 2.4 MB18/11/22 22:10:07 INFO util.GSet: capacity = 2^18 = 262144 entries18/11/22 22:10:07 INFO namenode.FSNamesystem: dfs.namenode.safemode.threshold-pct = 0.999000012874603318/11/22 22:10:07 INFO namenode.FSNamesystem: dfs.namenode.safemode.min.datanodes = 018/11/22 22:10:07 INFO namenode.FSNamesystem: dfs.namenode.safemode.extension = 3000018/11/22 22:10:07 INFO metrics.TopMetrics: NNTop conf: dfs.namenode.top.window.num.buckets = 1018/11/22 22:10:07 INFO metrics.TopMetrics: NNTop conf: dfs.namenode.top.num.users = 1018/11/22 22:10:07 INFO metrics.TopMetrics: NNTop conf: dfs.namenode.top.windows.minutes = 1,5,2518/11/22 22:10:07 INFO namenode.FSNamesystem: Retry cache on namenode is enabled18/11/22 22:10:07 INFO namenode.FSNamesystem: Retry cache will use 0.03 of total heap and retry cache entry expiry time is 600000 millis18/11/22 22:10:08 INFO util.GSet: Computing capacity for map NameNodeRetryCache18/11/22 22:10:08 INFO util.GSet: VM type = 64-bit18/11/22 22:10:08 INFO util.GSet: 0.029999999329447746% max memory 966.7 MB = 297.0 KB18/11/22 22:10:08 INFO util.GSet: capacity = 2^15 = 32768 entries18/11/22 22:10:08 INFO namenode.FSImage: Allocated new BlockPoolId: BP-1249797347-192.168.55.128-154294260834618/11/22 22:10:08 INFO common.Storage: Storage directory /var/data/hadoop/dfs/name has been successfully formatted.18/11/22 22:10:09 INFO namenode.FSImageFormatProtobuf: Saving image file /var/data/hadoop/dfs/name/current/fsimage.ckpt_0000000000000000000 using no compression18/11/22 22:10:10 INFO namenode.FSImageFormatProtobuf: Image file /var/data/hadoop/dfs/name/current/fsimage.ckpt_0000000000000000000 of size 351 bytes saved in 0 seconds.18/11/22 22:10:10 INFO namenode.NNStorageRetentionManager: Going to retain 1 images with txid >= 018/11/22 22:10:10 INFO util.ExitUtil: Exiting with status 018/11/22 22:10:10 INFO namenode.NameNode: SHUTDOWN_MSG: /************************************************************SHUTDOWN_MSG: Shutting down NameNode at node1/192.168.55.128************************************************************/
[root@node1 ~]# ll /var/data/hadoop/dfs/name/current/total 16-rw-r--r-- 1 root root 351 Nov 22 22:10 fsimage_0000000000000000000-rw-r--r-- 1 root root 62 Nov 22 22:10 fsimage_0000000000000000000.md5-rw-r--r-- 1 root root 2 Nov 22 22:10 seen_txid-rw-r--r-- 1 root root 207 Nov 22 22:10 VERSION
启动HDFS
[root@node1 ~]# start-dfs.shStarting namenodes on [node1]node1: starting namenode, logging to /opt/hadoop-2.7.3/logs/hadoop-root-namenode-node1.outnode3: starting datanode, logging to /opt/hadoop-2.7.3/logs/hadoop-root-datanode-node3.outnode2: starting datanode, logging to /opt/hadoop-2.7.3/logs/hadoop-root-datanode-node2.outnode1: starting datanode, logging to /opt/hadoop-2.7.3/logs/hadoop-root-datanode-node1.outStarting secondary namenodes [node2]node2: starting secondarynamenode, logging to /opt/hadoop-2.7.3/logs/hadoop-root-secondarynamenode-node2.out[root@node1 ~]#
查看三个节点上的Java进程：
node1
node2
node3
HDFS Web界面
打开
在”Datanodes”可以看到三个DataNode节点的信息：
