hadoop hdfs commands

First, the preparation conditions:1. Four Linux virtual machines (1 namenode nodes, 1 secondary nodes (secondary and 1 datanode shared), plus 2 datanode)2. Download the Hadoop version, this example uses the Hadoop-2.5.2 versionSecond, install Java JDKBest installed, JDK 1.7 is best for JDK 1.7 compatibility-IVH jdk-7u79-linux-/root/. Bash_profilejava_home=/usr/java/jdk1. 7 . 0_79path= $PATH: $JAVA _home/bin

The following subsections complement each other, and you will find a lot of interesting places to combine. Reprint please indicate source address: http://blog.csdn.net/lastsweetop/article/details/9065667 1. Topological distancesHere is a brief account of the computing distance of the network topology of Hadoop in a large number of scenarios, bandwidth is scarce resources, how to make full use of bandwidth, perfect computational cost and limiting fac

1. HDFs machine Migration, implementation sbin/stop-dfs.sh Error: Dchadoop010.dx.momo.com:no Namenode to stopDchadoop009.dx.momo.com:no Namenode to stopDchadoop010.dx.momo.com:no Datanode to stopDchadoop009.dx.momo.com:no Datanode to stopDchadoop011.dx.momo.com:no Datanode to stopStopping journal nodes [dchadoop009.dx.momo.com dchadoop010.dx.momo.com dchadoop011.dx.momo.com]Dchadoop010.dx.momo.com:no Journalnode to stopDchadoop009.dx.momo.com:no Journ

$handler.run (Server.java:1754)At this point, you can see the directory that holds the synchronization files/hadop-cdh-data/jddfs/nn/journalhdfs1 not found, SSH remote connection to the node to see that there is no such directory. Here, basically can be fixed to the problem, there are 2 ways to solve: one is to initialize the directory through the relevant command (I think this method is the correct way to solve the problem), and the second is to directly copy the normal Journalnode files over.

Hadoop is now a very hot big data running framework and platform, for this amazing big guy I am not clear, the previous time to ignore it to run HADOOP, look at its operation record storage part (Operation log), IMAGE records all the platform's file operation records, such as creating files, Delete files, rename and so on, here are some of my little observations.Formatting----InitializationThis is the initi

There was an article in detail about how to install Hadoop+hbase+zookeeper The title of the article is: Hadoop+hbase+zookeeper distributed cluster construction perfect operation Its website: http://blog.csdn.net/shatelang/article/details/7605939 This article is about hadoop1.0.0+hbase0.92.1+zookeeper3.3.4. The installation file versions are as follows: Please refer to the previous article for details, a

Data management and fault tolerance in HDFs1. Placement of data blocksEach data block 3 copies, just like above database A, this is because the data in the transmission process of any node is likely to fail (no way, cheap machine is like this), in order to ensure that the data can not be lost, so there are 3 copies, so that the hardware fault tolerance, ensure the accuracy of data transmission process.3 copies of the data, placed on two racks. For example, there are 2 copies of rack 1 above, and

is passed in, and the cancellation state of the cancellation iscancelled is true, exit the while loop directlyif(Canceler! = null canceler.iscancelled ()) {return; }Longnow = Monotonicnow ();//Calculates the current cycle end time. and stored in the curperiodend variable.LongCurperiodend = Curperiodstart + period;if(Now //wait for the next cycle so that Curreserve can addTry{Wait (curperiodend-now); }Catch(Interruptedexception e) {//Terminate throttle, and reset the interrupted state to ensure

First, Namenode maintains 2 sheets:1. File system directory structure, and meta-data information2. Correspondence between the file and the data block liststored in the Fsimage and loaded into memory at run time.Operation Log written to edits?Second, DataNodeStorage using block form. In Hadoop2, the default size is 128MB.The security of data is saved using a copy, which is the default number of 3.?Using the shell to access HDFsBin/hdfs dfs–xxx?Third, R

is append (), which allows data to be appended at the end of an existing file The progress () method is used to pass the callback interface, which notifies the application that the data is being written to Datenode. 1String localsrc = args[0];2String DST = args[1];3 //get file Read stream4InputStream in =NewInputStream (NewFileInputStream (LOCALSRC));5 6Configuration conf =NewConfiguration ();7FileSystem fs =Filesystem.get (Uri.create (DST), conf);8OutputStream out = Fs,create (NewPath

start HDFSStart-jobhistoryserver.shStart-mapred.sh starts mapreduce.Stop-all.sh stop HDFS and mapreduceStop-balancer.sh stops Load BalancingStop-dfs.sh stop HDFSStop-jobhistoryserver.sh stop job TracingStop-mapred.sh stops mapreduceTask-ControllerPart 2: Basic hadoop shell operationsNhadoop ShellIncluding: Namenode-format the DFS filesystem Secondarynamenode run the DFS secondary namenode Namenode run

. display the Datanode list $ Bin/hadoop dfsadmin-report 15. Retire Datanode node datanodename $ Bin/hadoop dfsadmin-decommission datanodename 16. The bin/hadoop dfsadmin-help command can list all currently supported commands. For example: *-Report: Reports basic HDFS statis

Hadoop Shell commands Use bin/hadoop FS 1. cat Description: outputs the content of the specified file in the path to stdout. Usage: hadoop fs-cat URI [URI…] Example: hadoopfs-cathdfs://host1:port1/file1hdfs://host2:port2/file2 hadoopfs-catfile:///file3/user/hadoop/

[cmd ...]Management commands for HDFs[Email protected] hadoop-2.7.3]$ bin/HDFs Dfsadminusage:hdfs dfsadminnote:administrative commands can only be run as the HDFs Superuser. [-report [-live] [-dead] [-Decommissioning]] [-safemode

After installing the Hadoop pseudo-distributed environment, executing the relevant commands (for example: Bin/hdfs dfs-ls) will appearWARN util. nativecodeloader:unable to load Native-hadoop library for your platform ... using Builtin-java classes where applicable, which is Because the installed Navtive packages and pl

DISTCP Parallel replication The same version of the Hadoop cluster Hadoop distcp Hdfs//namenode1/foo Hdfs//namenode2/bar Different versions of the Hadoop cluster (HDFs version), executed on the writing side

FS Shell Calling the file system (FS) shell command should use the form of Bin/hadoop FS Cat How to use: Hadoop fs-cat uri [uri ...] The path specifies the contents of the file to be exported to stdout. Example: Hadoop fs-cat Hdfs://host1:port1/file1 Hdfs://host2:p

A. Common Hadoop commands1. The FS command for Hadoop#查看hadoop所有的fs命令Hadoop FS#上传文件 (both put and copyfromlocal are upload commands)Hadoop fs-put jdk-7u55-linux-i586.tar.gz hdfs://hucc0

Introduction to some common commands in hadoop. Assume that the Hadoop installation directory HADOOP_HOME is homeadminhadoop. Start and close Hadoop1. open the HADOOP_HOME directory. 2. run the shbinstart-all.sh to close Hadoop1. go to HADOOP_HOM. suppose Hadoop's installation directory HADOOP_HOME is/home/admin/hadoop

1. The command format for HDFS operations is1.1hadoop fs-ls1.2 Hadoop fs-lsr1.3hadoop fs-mkdir1.4hadoop fs-put1.5hadoop fs-get1.6hadoop fs-text1.7hadoop fs-rm1.8hadoop fs-rmr2.hdfs when a block partition of data storage, if the file size exceeds block, then according to block size partition, rather than block sizes, divided into a block, is the actual data size.P