Course Outline and Content introduction:About 35 minutes per lesson, no less than 40 lecturesThe first chapter (11 speak)• Distributed and traditional stand-alone mode· Hadoop background and how it works· Analysis of the working principle of MapReduce• Analysis of the second generation Mr--yarn principle· Cloudera Manager 4.1.2 Installation· Cloudera Hadoop 4.1.2 Installation· CM under the cluster managemen
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 appears same but has minute differences
Hadoop fs {args}
Prepare hadoop streaming
Hadoop streaming allows you to create and run MAP/reduce jobs with any executable or script as the Mapper and/or the CER Cer.
1. Download hadoop streaming fit for your hadoop version
For hadoop2.4.0, you can visit the following website and download the JAR file:
Http://mvnrepository.com/art
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
Hadoop distcp Hftp://namenode1:50070/foo Hdfs://namenode2/bar
Archive of
Because HDFs is different from a common file system, Hadoop provides a powerful filesystem API to manipulate HDFs.
The core classes are Fsdatainputstream and Fsdataoutputstream.
Read operation:
We use Fsdatainputstream to read the specified file in HDFs (the first experiment), and we also demonstrate the ability to locate the file location of the class, and then start reading the file from the specified location (the second experiment).
The code i
Today, HDFS, the core of hadoop, is very important. It is a distributed file system. Why does hadoop support massive data storage? In fact, it depends mainly on the HDFS capability, mainly on the ability of HDFS to store massive data.
1. Why can HDFS store massive data?
In the beginning, let's think about this problem. I don't need to talk about the basic concepts of HDFS ~ We focus on usage rather than "re
Tags: hadoop Linux environment construction
Build a pseudo-distributed hadoop Environment
1. network connection between the host machine (Windows) and the client (Linux installed in a virtual machine.
A) The host-only host is connected to the client separately;
Benefits: Network isolation;
Disadvantage: the virtual machine cannot communicate with other servers;
B. The bridge host is in the same LAN as the c
combine multiple files into one ZIP file. Each file is compressed separately, and all files are stored at the end of the ZIP file. This attribute indicates that the ZIP file supports splitting at the file boundary. Each part contains one or more files in the zip compressed file.
Hadoop CompressionAlgorithmAdvantages and disadvantages
When considering how to compress data that will be processed by mapreduce, it is important to consider whether the
Inkfish original, do not reprint commercial nature, reproduced please indicate the source (http://blog.csdn.net/inkfish).
Hadoop is an open source cloud computing platform project under the Apache Foundation. Currently the latest version is Hadoop 0.20.1. The following is a blueprint for Hadoop 0.20.1, which describes how to install
Currently in Hadoop used more than lzo,gzip,snappy,bzip2 these 4 kinds of compression format, the author based on practical experience to introduce the advantages and disadvantages of these 4 compression formats and application scenarios, so that we in practice according to the actual situation to choose different compression format.
1 gzip compression
Advantages: The compression ratio is high, and the compression/decompression speed is relatively fas
to facilitate the MapReduce direct access to the relational database (mysql,oracle). Hadoop offers two classes of Dbinputformat and Dboutputformat. Through the Dbinputformat class, the database table data is read into HDFs, and the result set generated by MapReduce is imported into the database table according to the Dboutputformat class.error when executing mapreduce: java.io.IOException:com.mysql.jdbc.Driver, usually because the program cannot find
First, compile the Hadoop pluginFirst you need to compile the Hadoop plugin: Hadoop-eclipse-plugin-2.6.0.jar Before you can install it. Third-party compilation tutorial: Https://github.com/winghc/hadoop2x-eclipse-pluginIi. placing plugins and restarting eclipsePut the compiled plugin Hadoop-eclipse-plugin-2.6.0.jar int
Build a Hadoop development environment for Fedora 20
1. configuration information:
Operating System: fedora 20X86
Eclipse version: eclipse-jee-helios-SR2-linux-gtk.tar.gz (preferably use Galileo or Helios, otherwise there may be compatibility issues)
Hadoop version: hadoop-1.1.2.tar.gz
Ant: apache-ant-1.9.3-bin.tar.gz
2. Compile the
First, ready to run the required jar package1) Avro-1.7.4.jar2) Commons-cli-1.2.jar3) Commons-codec-1.4.jar4) Commons-collections-3.2.1.jar5) Commons-compress-1.4.1.jar6) Commons-configuration-1.6.jar7) Commons-io-2.4.jar8) Commons-lang-2.6.jar9) Commons-logging-1.2.jar) Commons-math3-3.1.1.jarOne) Commons-net-3.1.jarCurator-client-2.7.1.jar)Curator-recipes-2.7.1.jar)Gson-2.2.4.jar)Guava-20.0.jar)Hadoop-annotations-2.8.0.jar)
When Hadoop was started today, it was discovered that Datanode could not boot, and the following errors were found in the View log: Java.io.ioexception:file/opt/hadoop/tmp/mapred/system/jobtracker.info could only is replicated to 0 nodes, instead o F 1 at Org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock (fsnamesystem.java:1271) at Org.apache.hadoop.hdfs.server.namenode.NameNode.addBl
This morning, I helped a new person remotely build a hadoop cluster (1. in versions X or earlier than 0.22), I am deeply touched. Here I will write down the simplest Apache hadoop construction method and provide help to new users. I will try my best to explain it in detail. Click here to view the avatorhadoop construction steps.
1. Environment preparation:
1 ). machine preparation: the target machine must b
What is hadoop?
Before doing something, the first step is to know what, then why, and finally how ). However, after many years of project development, many developers get used to how first, then what, and finally why. This will only make them impetuous, at the same time, technologies are often misused in unsuitable scenarios.
The core designs in the hadoop framework are mapreduce and HDFS. The idea of mapre
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 StackOverflow
Following are the three commands which appears same but have minute differences Hadoop
Hadoop In The Big Data era (1): hadoop Installation
Hadoop In The Big Data era (II): hadoop script Parsing
To understand hadoop, you first need to understand hadoop data streams, just like learning about the servlet lifecycle.Ha
Hadoop Elephant Safari 010- using Eclipse to view Hadoop source code sinomThis is what I'm using. hadoop-1.1.2.tar.gz , this file can be downloaded at the following address:Official Address: http://archive.apache.org/dist/hadoop/core/hadoop-1.1.2/1. Unzip the
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