fs-count-q
Hadoop fs-count-q/path/to/directory
QUOTA remaining_quota space_quota Remaining_space_quota
none inf 54975581388800 5277747062870
dir_count file_count content_size file_ NAME
3922 418464 16565944775310 hdfs://master:54310/path/to/directory
Here for a change of line, and added a number of column labels, you can more easily see:
Seventh column, Content_s
Hadoop FS: The widest range of users can operate any file system.
Hadoop DFS and HDFs dfs: only HDFs file system related (including operations with local FS) can be manipulated, the former has been deprecated, generally using the latter.
The following reference from StackOv
to the destination path. This command allows for multiple source paths, at which point the target path must be a directory;
1
Hadoop fs-get/user/hadoop/file LocalFile
Copy files to local file system;
1
Hadoop fs-put Local
Hadoop FS: Use the widest range of surfaces to manipulate any file system.Hadoop DFS and HDFs DFS: can only operate on HDFs file system-related (including operations with local FS), which is already deprecated, typically using the latter.The following reference is from StackOverflowFollowing is the three commands which
can achieve hot swapping without restarting the computer and Hadoop services. The start-balancer. sh script in the Hadoop H ome/bin directory is the start script of the task. The startup command is 'start − balancer. sh script in the HadoopHome/bin directory, which is the startup script of the task. Start command: 'hadoop_home/bin/start-balancer.sh-threshold'
Several parameters that affect Balancer:
-Thr
closing the stream in the finally clause, and also For copying bytes between the input stream and the output stream (System.out, in this case). The last of the arguments to the Copybytes () method is the buffer size used for copying and whether to close the streams whe n the copy is complete. We close the input stream ourselves, and system.out doesn ' t need to be closed. We used the nearest Ioutils class in Had
HDFS file system provides an API for an abstract File System Based on hadoop, which supports stream-based access to data in the file system.Features:1. Support for ultra-large files2. Detect and quickly respond to hardware faults (fault detection and Automatic Recovery)3. Streaming Data Access focuses on data throughput rather than data response speed4. Simplified consistency model with one write and multip
Reprinted please indicate the source, http://blog.csdn.net/lastsweetop/article/details/9001467
All source code on GitHub, https://github.com/lastsweetop/styhadoopReading data using hadoop URL is a simple way to read HDFS data through java.net. the URL opens a stream, but before that, you must call its seturlstreamhandlerfactory method to set it to fsurlstreamhandlerfactory (the factory retrieves the parsing
Not much to say, directly on the code.CodePackage zhouls.bigdata.myWholeHadoop.HDFS.hdfs7;Import java.io.IOException;Import Java.net.URI;Import java.net.URISyntaxException;Import org.apache.hadoop.conf.Configuration;Import Org.apache.hadoop.fs.FSDataInputStream;Import Org.apache.hadoop.fs.FSDataOutputStream;Import Org.apache.hadoop.fs.FileStatus;Import Org.apache.hadoop.fs.FileSystem;Import Org.apache.hadoop.fs.FileUtil;Import Org.apache.hadoop.fs.Path;Import Org.apache.hadoop.fs.PathFilter;Impo
=org.apache.hadoop.hdfs.tools.dfsadminhadoop_opts= "$HADOOP _opts $HADOOP _client_opts"...A more plausible explanation.Unconvinced, and these excerpts made more sense to me:
FS relates to a generic the file system which can point to any of the file systems like local, HDFS etc. But Dfs was very specific to
-default.xml file, as shown in 4.2.
Fig 4.2
The ds. Block. name parameter in indicates the block size. The value is 67, 108, 864 bytes, and can be converted to 64 MB. If we don't want a 64 MB size, We can override this value in the core-site.xml. Note that the unit is byte.
2.3 Copies
Fig 4.3
As shown in Figure 4.3, the default number of copies is 3. This means that each data block in HDFS has three copies. Of course, each
. Options of HDFS shell operation commands
Option name
Format
Description
-Ls
-Ls
View the current directory structure of the specified path
-LSR
-LSR
Recursively view the directory structure of a specified path
-Du
-Du
Measure the file size in the directory.
-DUS
-DUS
Summarize the file (folder) size in the statistics directory
-Count
recognize IP must have JDK1.7, and JDK environment variables must be configured well. Configuration environment variable: VI ~/.bash_profile #全局变量:/etc/profile at the end of the file add: Export Java_home=/usr/java/default export path= $PATH: $JAVA _ Home/bin source ~/.bash_profile Refresh environment variable file firewall temporarily shut down. Upload tar and unzip (TAR-ZXVF tar package name). and configure the environment variable of HADOOP export
file into one or more blocks, which are stored in a set of data nodes. A file or directory operation that the name node uses to manipulate the file namespace, such as open, close, rename, and so on. It also determines the mapping of blocks to data nodes. Data node to be responsible for read and write requests from file system customers. The data node also performs block creation, deletion, and block copy instructions from the name node.The
/lib/eclipsehttp://www.blogjava.net/hongjunli/archive/2007/08/15/137054.html troubleshoot viewing. class filesA typical Hadoop workflow generates data files (such as log files) elsewhere, and then copies them into HDFs, which is then processed by MapReduce. Typically, an HDFs file is not read directly. They rely on the MapReduce framework to read. and resolves it
://www.blogjava.net/hongjunli/archive/2007/08/15/137054.html troubleshoot viewing. class filesA typical Hadoop workflow generates data files (such as log files) elsewhere, and then copies them into HDFs, which is then processed by mapreduce, usually without directly reading an HDFs file, which is read by the MapReduce framework. and resolves it to a separate reco
The Hadoop Distributed File system is the Hadoop distributed FileSystem.When the size of a dataset exceeds the storage capacity of a single physical computer, it is necessary to partition it (Partition) and store it on several separate computers, managing a file system that spans multiple computer stores in the network as a distributed File system (distributed FileSystem).The system architecture and network
Http://www.cnblogs.com/sxt-zkys/archive/2017/07/24/7229857.html
Hadoop's HDFs
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HDFs Introduction
HDFS (Hadoop Distributed File System)
Tags: mod file copy ima time LSP tab version Execute file cinSince HDFs is a distributed file system for accessing data, the operation of HDFs is the basic operation of the file system, such as file creation, modification, deletion, modification permissions, folder creation, deletion, renaming, etc. The operations command for
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