Note:this article is originally posted on a previous version of the 500px engineering blog. A lot has changed since it is originally posted on Feb 1, 2015. In the future posts, we'll be covering how we image classification solution has and evolved what other interesting Mach INE learning projects we have.
Tldr:this Post provides an overview the how to perform large scale image classification using Hadoop streaming. Component individually and identify
same key to the same reduce processing, we need to design it as key = word, value = URL + Word Frequency
Figure 2 input/output of the combin Process
2.3reduce Process
The reduce process is actually a merge process. You only need to merge the values of the same key value into the format required by the inverted index.
Figure 3 input/output of reduce Process
3. Source Code
Package reverseindex; import Java. io. ioexception; import Java. util. stringtokenizer; import Org. apache.
Description: Compile hadoop program using eclipse in window and run on hadoop. the following error occurs:
11/10/28 16:05:53 info mapred. jobclient: running job: job_201110281103_000311/10/28 16:05:54 info mapred. jobclient: Map 0% reduce 0%11/10/28 16:06:05 info mapred. jobclient: task id: attempt_201110281103_0003_m_000002_0, status: FailedOrg. apache. hadoop.
Hadoop interview questions (1) and hadoop interview questions
I. Q :
1. Briefly describe how to install and configure an apache open-source version of hadoop. You only need to describe it. You do not need to list the complete steps and the steps are better.
1) install JDK and configure environment variables (/etc/profile)
2) disable the Firewall
3) configure the
Today the Hadoop authoritative Guide Weather Data sample code runs through the Hadoop cluster and records it.
Before the Baidu/google how also did not find how to map-reduce way to run in the cluster every step of the specific description, after a painful headless fly-style groping, success, a good mood ...
1 Preparing the Weather forecast data (simplified version of the data on the authoritative guide 5-9
Hadoop Elephant Safari 006- Installing the Hadoop environment sinom > Our hardware computer is running . windows7x64 windows7 installed vmware10 virtual machine, vmware centos6.5 operating system, centos jdk1.6.0_45 centos securecrsecurefx Everything is available, Hadoop should be installed , but There are many versions of
We know that the Hadoop cluster is fault-tolerant, distributed and so on, why it has these characteristics, the following is one of the principles.
Distributed clusters typically contain a very large number of machines, and due to the limitations of the rack slots and switch ports, the larger distributed clusters typically span several racks, and the machines on multiple racks form a distributed cluster. The network speed between the machines in the
Because Hadoop is still in its early stage of rapid development, and it is open-source, its version has been very messy. Some of the main features of Hadoop include:
Append: Supports file appending. If you want to use HBase, you need this feature.
RAID: to ensure data reliability, you can introduce verification codes to reduce the number of data blocks. Link: https://issues.apache.org/jira/browse/HDFS/c
Write scalable, distributed data-intensive programs and basics
Understanding Hadoop and MapReduce
Write and run a basic MapReduce program
1. What is HadoopHadoop is an open-source framework for writing and running distributed applications to handle large-scale data.What makes Hadoop unique is the following points:
Convenient--hadoop run on a
Environment[Email protected] soft]#Cat/etc/Issuecentos Release6.5(Final) Kernel \ r \m[[email protected] soft]#uname-Alinux vm80282.6. +-431. el6.x86_64 #1SMP Fri Nov A Geneva: the: theUtc -x86_64 x86_64 x86_64 gnu/Linux[[email protected] soft]# Hadoop versionhadoop2.7.1Subversion https://git-wip-us.apache.org/repos/asf/hadoop.git-r 15ecc87ccf4a0228f35af08fc56de536e6ce657aCompiled by Jenkins on -- .-29t06:04zcompiled with Protoc2.5.0From source with c
1. The virtual machine installation hadoop,windows cannot access the Hadoop Web page http://master:50070/through the host name. Windows Ping Master also pings the method: Add Linux under Windows native C:\Windows\System32\drivers\etc\hosts files Hosts configure the hostname and IP address of the Hadoop machine to add in.
Issue 2, Windows Eclipse runni
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
Overview: This is a brief introduction to the hadoop ecosystem, from its origins to relative application technical points: 1. hadoop core includes Common, HDFS and MapReduce; 2.Pig, Hbase, Hive, Zookeeper; 3. hadoop log analysis tool Chukwa; 4. problems solved by MR: massive input data, simple task division and cluster computing environment; 5. execution Process
This article is derived from the deep analysis of Hadoop Technology Insider design and implementation principles of Hadoop common and HDFs architectureFirst, the basic concept of Hadoop
Hadoop is an open source distributed computing platform under the Apache Foundation, with the core of the
I. Introduction to the Hadoop releaseThere are many Hadoop distributions available, with Intel distributions, Huawei Distributions, Cloudera Distributions (CDH), hortonworks versions, and so on, all of which are based on Apache Hadoop, and there are so many versions is due to Apache Hadoop's Open source agreement: Anyone can modify it and publish/sell it as an op
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
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.