Install times wrong: Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.7:run (site) on project Hadoop-hdfs:an Ant B Uildexception has occured:input file/usr/local/hadoop-2.6.0-stable/hadoop-2.6.0-src/hadoop-hdfs
Not much to say, directly on the code.CodePackage zhouls.bigdata.myWholeHadoop.HDFS.hdfs5;Import java.io.IOException;Import Java.net.URI;Import java.net.URISyntaxException;Import org.apache.hadoop.conf.Configuration;Import Org.apache.hadoop.fs.FileSystem;Import Org.apache.hadoop.fs.Path;/**** @author* @function Copying from the Local file system to HDFS**/public class Copyinglocalfiletohdfs{/*** @function M
The project needs to copy the local files to HDFs, because I am lazy, so use good Java program through the Hadoop.FileSystem.CopyFromLocalFile method to achieve. The following exception was encountered while running in local (Window 7 environment) Local mode:An exception or
PHP used Thrift to upload local files to Hadoop's hdfs by calling SHELL, but the upload efficiency was low. another user pointed out that he had to use other methods .? Environment: The php runtime environment is nginx + php-fpm? Because hadoop enables permission control, PHP calls SHELL to upload local files to
PHP calls the shell to upload local files into Hadoop's HDFs
Originally used to upload thrift, but its low upload efficiency, another person heinous, had to choose other methods.
?
Environment:
PHP operating Environment for Nginx + PHP-FPM
?
Because Hadoop has permission control enabled, there is no permission to use PHP directly to invoke Shel for uploadi
Hadoop version: 2.6.0This article is from the Official document translation, reproduced please respect the work of the translator, note the following links:Http://www.cnblogs.com/zhangningbo/p/4146296.htmlBackground
In HDFs, the data is usually read by Datanode. However, when a client reads a file to a Datanode request, Datanode reads the file from disk and sends the data to the client via a TCP socke
Put the program into a jar pack and put it on Linux.
Go to the directory to execute the command Hadoop jar Mapreducer.jar/home/clq/export/java/count.jar hdfs://ubuntu:9000/out06/count/
The above one is a local file, one is the upload HDFs location
After success appears: Print out the characters you want to print.
"), also add our standard Spark classpath, built using compute-classpath.sh.
Classpath= ' $FWDIR/bin/compute-classpath.sh '
Classdata-path= "$SPARK _qiutest_jar: $CLASSPATH"
# find Java Binary
If [-N "${java_home}"]; Then
Runner= "${java_home}/bin/java"
Else
If [' command-v Java ']; Then
Runner= "Java"
Else
echo "Java_home is not set" >2
Exit 1
Fi
Fi
If ["$SPARK _print_launch_command" = = "1"]; Then
Echo-n "Spark Command:"
echo "$RUNNER"-CP "$CLASSPATH" "$@"
echo "=============================
Copy local files to the Hadoop File System
// Copy the local file to the Hadoop File System// Currently, other Hadoop file systems do not call the progress () method when writing files.
current directory is not found. If this directory is created, the files in it can be listed.
Run the following command to put a file from the local file system into HDFS: % hadoop FS-copyfromlocal/home/Norris/data/hadoop/weatherdata.txt/user/Norris/weatherdata.txt put the local
now let's take a closer look at the FileSystem class for Hadoop. This class is used to interact with Hadoop's file system. While we are mainly targeting HDFS here, we should let our code use only abstract class filesystem so that our code can interact with any Hadoop file system. When we write the test code, we can test it with the
-cp/user/hadoop/file1/user/hadoop/file2 Hadoop fs-cp/user/hadoop/file1/user/hadoop/file2/user/hadoop/ Dir
return value:
Successfully returns 0, failure returns-1. du
How to use: Hadoop
returns-1.9:dusHow to use: Hadoop fs-dus Displays the size of the file.10:expungeHow to use: Hadoop fs-expungeEmpty the Recycle Bin. Refer to the HDFs design documentation for more information about the properties of the Recycle Bin.11:getHow to use:Hadoop fs-get [-IGNORECRC] [-CRC] Copy the file to the
information on trash feature.
Get
Usage: hadoop FS-Get [-ignorecrc] [-CRC]
Copy files to the local file system. files that fail the CRC check may be copied with the-ignorecrc option. Files and CRCs may be copied using the-CRC option.
Example:
Hadoop FS-Get/user/hadoop/fi
Introduction
Prerequisites and Design Objectives
Hardware error
Streaming data access
Large data sets
A simple consistency model
"Mobile computing is more cost effective than moving data"
Portability between heterogeneous software and hardware platforms
Namenode and Datanode
File System namespace (namespace)
Data replication
Copy storage: One of the most starting steps
, because there is no way to re-assemble the file blocks in each datanodes. Therefore, it is necessary to ensure that namenode is reliable enough. hadoop provides two mechanisms to ensure data security in namenode. The first mechanism is to back up persistent information on namenode. Hadoop can be configured to allow namenode to write persistent information to multiple places, and these write operations are
usage information for all commands is displayed.
LS Hadoop fs–lspath[path ...] Lists files and directories, and each entry point displays the file name, permissions, owner, group, size, and modification time. The file entry points also display their copy coefficients.
LSR Hadoop FS–LSR path [path ...] The recursive version of LS.
mkdir
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