advantages of hadoop

First, download the Hadoop websitehttp://hadoop.apache.orghttps://archive.apache.org/dist/hadoop/common/hadoop-2.6.0 Administrator Identity Decompression D:\Hadoop\hadoop-2.6.0Second, the download of winutilsAlso need to download Winutils.exe,requires a corresponding version

Part 1: hadoop BinThe following hadoop bin is based on the actual needs of the project:Hadoop ShellHadoop-config.sh, which is used to assign values to some variablesHadoop_home (hadoop installation directory ).Hadoop_conf_dir (hadoop configuration file directory ). Hadoop_slaves (-- the address of the file specified by

Ubuntu installation (Here I do not catch a map, just cite a URL, I believe that everyone's ability)Ubuntu Installation Reference Tutorial: http://jingyan.baidu.com/article/14bd256e0ca52ebb6d26129c.htmlNote the following points:1, set the virtual machine's IP, click the network connection icon in the bottom right corner of the virtual machine, select "Bridge mode", so as to assign to your LAN IP, this is very important because the back Hadoop to use th

Http://devsolvd.com/questions/hadoop-unable-to-load-native-hadoop-library-for-your-platform-error-on-centos The answer depends ... I just installed Hadoop 2.6 from Tarball on 64-bit CentOS 6.6. The Hadoop install did indeed come with a prebuilt 64-bit native library. For my install, it's here: /opt/

Read files For more information about the file reading mechanism, see: The client calls the open () method of the filesystem object (corresponding to the HDFS file system, and calls the distributedfilesystem object) to open the file (that is, the first step in the figure ), distributedfilesystem uses Remote Procedure Call to call namenode to obtain the location of the first several blocks of the file (step 2 ). For each block, namenode returns the address information of all namenode that owns t

in the Hadoop Eclipse Development Environment Building In this article, the 15th.) mentions permission-related exceptions, as follows:15/01/30 10:08:17 WARN util. nativecodeloader:unable to load Native-hadoop library for your platform ... using Builtin-java classes where applicable15/ 01/30 10:08:17 ERROR Security. Usergroupinformation:priviledgedactionexception As:zhangchao3 cause:java.io.IOException:Faile

Pre-Preparation 1. Create a Hadoop-related directory (easy to manage) 2, give Hadoop users and all group permissions to the/opt/* directorysudo chrown-r hadoop:hadoop/opt/*3, JDK installation and configuration configuration Hdfs/yarn/mamreduce1, decompression HadoopTAR-ZXF hadoop-2.5.0.tar.gz-c/opt/modules/(delete Doc's help document, save space) rm-rf/opt/module

-p '-F/HOME/U/.SSH/ID_DSASsh-keygen indicates that the key is generated-T means the specified generated key typeDSA is the meaning of DSA key authentication, that is, the key type-P provides a passphrase-f Specifies the generated key file(4) # cat/home/u/.ssh/id_dsa.pub >>/home/u/.ssh/authorized_keys# Add the public key to the public key file for authentication, Authorized_keys is the public key file for authentication(5) # Ssh-version# Verify that SSH installation is complete and the correct in

additional openssh-clients(3) # Mkdir-p ~/.ssh # Assume that after you install SSH, these folders are not actively generated by yourself, please create your own(4) # ssh-keygen-t Dsa-p "-F ~/.SSH/ID_DSASsh-keygen indicates that the key is generated-T means the specified generated key typeDSA is the meaning of DSA key authentication, that is, the key type-P provides a passphrase-f Specifies the generated key file(5) # cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys# Add the public key to the pub

the node's shared space, while the operating system on each node runs only the service of the application and stores the application files.To sum up, the construction of a cluster system requires at least two servers, but also need to have serial cable, cluster software and shared storage devices.Server Cluster Technology features and functions ofHigh Availability and scalability1. Highly adaptableFor some real-time applications, it is necessary to keep the service running 24 hours a day, and b

server to handle a single task. There is no virtual server or management layer in the real product cluster, so there is no excess performance loss. Hadoop works best on Linux systems and operates directly on the underlying hardware infrastructure. This means that Hadoop is actually working directly on the virtual machine. This has unparalleled advantages in cost

Knowing and learning about Hadoop, we have to understand the composition of Hadoop, and based on my own experience, I introduce the Hadoop component, the big data processing process, and the three aspects of Hadoop core: Hadoop Components 650) this.width=650;

Various tangle period Ubuntu installs countless times Hadoop various versions tried countless times tragedy then see this www.linuxidc.com/Linux/2013-01/78391.htm or tragedy, slightly modifiedFirst, install the JDK1. Download and installsudo apt-get install OPENJDK-7-JDKRequired to enter the current user password when entering the password, enter;Required input yes/no, enter Yes, carriage return, all the way down the installation completed;2. Enter ja

Make sure that the three machines have the same user name and install the same directory *************SSH Non-key login simple introduction (before building a local pseudo-distributed, it is generated, now the three machines of the public key private key is the same, so the following is not configured)Stand-alone operation:Generate Key: Command ssh-keygen-t RSA then four carriage returnCopy the key to native: command Ssh-copy-id hadoop-senior.zuoyan.c

1, the main learning of Hadoop in the four framework: HDFs, MapReduce, Hive, HBase. These four frameworks are the most core of Hadoop, the most difficult to learn, but also the most widely used.2, familiar with the basic knowledge of Hadoop and the required knowledge such as Java Foundation,Linux Environment, Linux common commands 3. Some basic knowledge of Hadoo

Using HDFS to store small files is not economical, because each file is stored in a block, and the metadata of each block is stored in the namenode memory. Therefore, a large number of small files, it will eat a lot of namenode memory. (Note: A small file occupies one block, but the size of this block is not a set value. For example, each block is set to 128 MB, but a 1 MB file exists in a block, the actual size of datanode hard disk is 1 m, not 128 M. Therefore, the non-economic nature here ref

grouping (partition) The Hadoop streaming framework defaults to '/t ' as the key and the remainder as value, using '/t ' as the delimiter,If there is no '/t ' separator, the entire row is key; the key/tvalue pair is also used as the input for reduce in the map.-D stream.map.output.field.separator Specifies the split key separator, which defaults to/t-D stream.num.map.output.key.fields Select key Range-D map.output.key.field.separator Specifies the se

Tags: hadoop mysql map-reduce import export mysqlto 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. when running MapRe

Problems with the original Hadoop MapReduce frameworkThe MapReduce framework diagram of the original HadoopThe process and design ideas of the original MapReduce program can be clearly seen: First the user program (Jobclient) submits a job,job message sent to the job Tracker , the job Tracker is the center of the map-reduce framework, and he needs to communicate with the machine in the cluster (HEARTBE at), you need to manage which programs s

complete. 2. install and configure Hadoop (1) download the installation package from the Hadoop website and decompress it. The version I use here is the hadoop-1.2.1. $ Sudo tar-zxvf hadoop-1.2.1.tar.gz (2) Hadoop Configuration You can start a