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
(1) First create Java projectSelect File->new->java Project on the Eclipse menu.and is named UploadFile.(2) Add the necessary Hadoop jar packagesRight-click the JRE System Library and select Configure build path under Build path.Then select Add External Jars. Add the jar package and all the jar packages under Lib to your extracted Hadoop source directory.All jar packages in the Lib directory.(3) Join the Up
This article has agreed:Dn:datanodeTt:tasktrackerNn:namenodeSnn:secondry NameNodeJt:jobtrackerThis article describes the communication protocol between the Hadoop nodes and the client.Hadoop communication is based on RPC, a detailed introduction to RPC you can refer to "Hadoop RPC mechanism introduce Avro into the Hadoop RPC mechanism"Communication between nodes
This article will go on to the wordcount example in the previous article to abstract the simplest process and explore how the System Scheduling works in the mapreduce operation process.
Scenario 1: Separate data from operations
Wordcount is the hadoop helloworld program. It counts the number of times each word appears. The process is as follows:
Now I will describe this process in text.
1. The client submits a job and sends mapreduce programs and dat
Once Hadoop is installed, you will often be prompted with a warning:
WARN util. nativecodeloader:unable to load Native-hadoop library for your platform ...
Using Builtin-java classes where applicableSearched a lot of articles, all say is related to the system bit number, I use CentOS 6.5 64-bit operating system.
The first two days in the Docker image to find a step to solve the problem, the pro tried
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
The compilation process is very long, the mistakes are endless, need patience and patience!! 1. Preparation of the environment and software
Operating system: Centos6.4 64-bit
JDK:JDK-7U80-LINUX-X64.RPM, do not use 1.8
Maven:apache-maven-3.3.3-bin.tar.gz
protobuf:protobuf-2.5.0.tar.gz Note: Google's products, preferably in advance Baidu prepared this document
Hadoop src:hadoop-2.5
Preface
I still have reverence for technology.Hadoop Overview
Hadoop is an open-source distributed cloud computing platform based on the MAP/reduce model to process massive data.Offline analysis tools. Developed based on Java and built on HDFS, which was first proposed by Google. If you are interested, you can get started with Google trigger: GFS, mapreduce, and bigtable, I will not go into details here, because there are too many materials on the Int
Org. apache. hadoop. IPC. remoteException: Org. apache. hadoop. HDFS. server. namenode. safemodeexception: cannot delete/tmp/hadoop/mapred/system. name node is in safe mode.
The ratio of reported blocks 0.7857 has not reached the threshold 0.9990. Safe mode will be turned off automatically.
At org. Apache. hadoop. HDFS
DescriptionHadoop version: hadoop-2.5.0-cdh5.3.6Environment: centos6.4Must be networkedHadoop Download URL: http://archive.cloudera.com/cdh5/cdh/5/In fact, compiling is really manual work, according to the official instructions, step by step down to do it, but always meet the pit.Compile steps :1, download the source code, decompression, in this case, extracted to/opt/softwares:Command: TAR-ZXVF hadoop-2.5.
1. Introduction to HadoopHadoop is an open-source distributed computing platform under the Apache Software Foundation, which provides users with a transparent distributed architecture of the underlying details of the system, and through Hadoop, it is possible to organize a large number of inexpensive machine computing resources to solve the problem of massive data processing that cannot be solved by a single machine.
The Hadoop version of this blog is Hadoop 0.20.2.Installing Hadoop-0.20.2-eclipse-plugin.jar
To download the Hadoop-0.20.2-eclipse-plugin.jar file and add it to the Eclipse plug-in library, add a method that is simple: Locate the plugins directory under the Eclipse installation directory, copy directly to this
Hadoop exception and handling Summary-01 (pony-original), hadoop-01
Test environment:
Local: MyEclipse
Cluster: Vmware 11 + 6 Centos 6.5
Hadoop version: 2.4.0 (configured as automatic HA)
Test Background:
After four normal tests of the MapReduce Program (hereinafter referred to as MapReduce), a new MR program is executed, and the console information of MyEclipse
Hadoop learning 2: hadoop LearningAfter building a pseudo-distributed system:Introduction to pseudo distributed installation: http://www.powerxing.com/install-hadoop/
Exercise 1 compile a Java program to implement the followingFunction:
1. In HDFSUpload files
2. From HDFSDownload filesTo local
3.Show file directory
4.Move files
5.Create folder
6.Remove folder
everything is OK on the Namenode node, and there is no prompt for this information, but the following message appears on Datanode:15/01/14 16:42:09 WARN util. nativecodeloader:unable to load Native-hadoop library for your platform ... using Builtin-java classes where applicableafter checking the original is Datanode sub-node /home/hadoop/hadoop2.2/lib directory does not have native folder, and Namenode abov
Hadoop ++ is a non-invasive Optimization of hadoop map reduce. It improves query and connection performance by customizing functions such as split in hadoop framework. The project is hosted by Professor Jens dittrich at the University of Saarland, Germany. The project homepage is http://infosys.uni-saarland.de/hadoop?#
Original article: http://hadoop.apache.org/common/docs/r0.23.0/hadoop-yarn/hadoop-yarn-site/CapacityScheduler.html
This document describes capacityscheduler, a pluggable hadoop scheduler that allows multiple users to securely share a large cluster, their applications can obtain the required resources within the capacity limit.
Overview
Capacityscheduler is design
, file random modification a file can have only one writer, only support append.Data form of 3.HDFSThe file is cut into a fixed-size block, the default block size is 64MB, the size of the block can be configured, if the file size is less than 64MB, it is stored separately into a block. A file storage method is divided into blocks by size, stored on different nodes, with three replicas per block by default.HDFs Data Write Process: HDFs Data Read process: 4.MapReduce: Google's MapReduce open sou
Deploy Hadoop cluster service in CentOSGuideHadoop is a Distributed System infrastructure developed by the Apache Foundation. Hadoop implements a Distributed File System (HDFS. HDFS features high fault tolerance and is designed to be deployed on low-cost hardware. It also provides high throughput to access application data, suitable for applications with large datasets. HDFS relaxed the requirements of POSI
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