balancing process does not affect the normal operation of namenode.
Principles of Hadoop HDFS data load balancing
The core of the data balancing process is a data balancing algorithm that continuously iterates the data balancing logic until the data in the cluster is balanced. The logic of each iteration of the data balancing algorithm is as follows:
The procedure is as follows:
The Rebalancing Server f
recognize IP must have JDK1.7, and JDK environment variables must be configured well. Configuration environment variable: VI ~/.bash_profile #全局变量:/etc/profile at the end of the file add: Export Java_home=/usr/java/default export path= $PATH: $JAVA _ Home/bin source ~/.bash_profile Refresh environment variable file firewall temporarily shut down. Upload tar and unzip (TAR-ZXVF tar package name). and configure the environment variable of HADOOP export
Concept
HDFS
HDFS (Hadoop distributed FileSystem) is a file system designed specifically for large-scale distributed data processing in a framework such as MapReduce. A large data set (100TB) can be stored in HDFs as a single file, and most other file systems are powerless to achieve this. Data blocks (block)
The def
multiple files into a large file to HDFs processing (high efficiency) after processing to meet the use of MapReduce, one of the principles of mapreduce processing is to cut the input data into chunks, which can be processed in parallel on more than one computer, In Hadoop terms these are referred to as input shards, which should be small enough to achieve granular parallelism. It can't be too small.Fsdatai
connect to the Hadoop distribution also has not been kettle support, you can fill in the corresponding information requirements Pentaho develop one.There are 1 more cases where the Hadoop distribution is already supported by Kettle and has built-in plugins.3 is configured.3.1 Stop application is if kettle in the run first stop him.3.2 Open the installation folder our side is kettle, so that's spoon. File p
core of Hadoop is HDFs and MapReduce, and both are theoretical foundations, not specific, high-level applications, and Hadoop has a number of classic sub-projects, such as HBase, Hive, which are developed based on HDFs and MapReduce. To understand Hadoop, you have to know w
://www.blogjava.net/hongjunli/archive/2007/08/15/137054.html troubleshoot viewing. class filesA typical Hadoop workflow generates data files (such as log files) elsewhere, and then copies them into HDFs, which is then processed by mapreduce, usually without directly reading an HDFs file, which is read by the MapReduce framework. and resolves it to a separate reco
http://blog.csdn.net/pipisorry/article/details/51340838the difference between ' Hadoop DFS ' and ' Hadoop FS 'While exploring HDFs, I came across these II syntaxes for querying HDFs:> Hadoop DFS> Hadoop FSWhy we have both differen
Exception descriptionIn the case of an unknown hostname when you format the Hadoop namenode-format command on HDFS, the exception information is as follows:[Plain]View PlainCopy
[Email protected] bin]$ Hadoop Namenode-format
11/06/22 07:33:31 INFO Namenode. Namenode:startup_msg:
/************************************************************
Startup_msg:s
The Hadoop Distributed File System (HDFS) is designed to be suitable for distributed file systems running on common hardware (commodity hardware). It has a lot in common with existing Distributed file systems. But at the same time, the difference between it and other distributed file systems is obvious. HDFs is a highly fault-tolerant system that is suitable for
Http://www.cnblogs.com/sxt-zkys/archive/2017/07/24/7229857.html
Hadoop's HDFs
Copyright Notice: This article is Yunshuxueyuan original article.If you want to reprint please indicate the source: http://www.cnblogs.com/sxt-zkys/QQ Technology Group: 299142667
HDFs Introduction
HDFS (Hadoop Distributed File System)
also has not been kettle support, you can fill in the corresponding information requirements Pentaho develop one.There are 1 more cases where the Hadoop distribution is already supported by Kettle and has built-in plugins.3 is configured.3.1 Stop application is if kettle in the run first stop him.3.2 Open the installation folder our side is kettle, so that's spoon. File path:3.3 Edit Plugin.properties file3.4 Change a configuration value to circle th
the/etc/sysconfig/network file:
Networking=yes
Networking_ipv6=yes
hostname=localhost.localdomain
Visible, the execution hostname gets the value of the hostname configured here.
Solving Method
Modify the hostname value in the/etc/sysconfig/network to localhost, or the host name that you specify, to ensure that localhost is mapped to the correct IP address in the/etc/hosts file, and then restart the Network service:
[root@localhost bin]#/etc/rc.d/init.d/network restart
shutting down interfa
some formats in text format
12.setrepHadoop fs-setrep-r 3 Change the number of copies of a file in HDFs, the number 3 in the above command is the number of copies set, and the-r option allows you to recursively change the number of copies of all directories + files in a directory
13.statHdoop fs-stat [format] Returns the status information for the corresponding path[format] Optional parameters are:%b (file size),%o (block size),%n (file n
Reprint please indicate from 36 Big Data (36dsj.com): 36 Big Data»hadoop Distributed File System HDFs works in detailTransfer Note: After reading this article, I feel that the content is more understandable, so share it to support a bit.Hadoop Distributed File System (HDFS) is a distributed file system designed to run on common hardware.
HDFs Add Delete nodes and perform HDFs balance
Mode 1: Static add Datanode, stop Namenode mode
1. Stop Namenode
2. Modify the slaves file and update to each node
3. Start Namenode
4. Execute the Hadoop balance command. (This is used for the balance cluster and is not required if you are just adding a node)
------
Preparatory work:
1, install the Hadoop;
2. Create a Helloworld.jar package, this article creates a jar package under the Linux shell:
Writing Helloworld.java filespublic class HelloWorld{public static void Main (String []args) throws Exception{System.out.println ("Hello World");}
}
Javac Helloworld.java is compiled and gets Helloworld.classIn the catalogue CV MANIFEST.MF file:manifest-version:1.0CREATED-BY:JDK1.6.0_45 (Sun Microsystems Inc.)Main-cl
Statement
This article is based on CentOS 6.x + CDH 5.x
HTTPFS, what's the use of HTTPFS to do these two things?
With Httpfs you can manage files on HDFs in your browser
HTTPFS also provides a set of restful APIs that can be used to manage HDFs
It's a very simple thing, but it's very practical. Install HTTPFS in the cluster to find a machine that can access
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