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This paper is an excerpt from the book "The Authoritative Guide to Hadoop", published by Tsinghua University Press, which is the author of Tom White, the School of Data Science and engineering, East China Normal University. This book begins with the origins of Hadoop, and integrates theory and practice to introduce Hadoop as an ideal tool for high-performance processing of massive datasets. The book consists of 16 chapters, 3 appendices, covering topics including: Haddoop;mapreduce;hadoop Distributed file system; Hadoop I/O, MapReduce application Open ...

Kafka configures SASL authentication and permission fulfillment documentation. First, the release notes This example uses: zookeeper-3.4.10, kafka_2.11-0.11.0.0. zookeeper version no requirements, kafka must use version 0.8 or later. Second, zookeeper configuration SASLzookeeper cluster or single node configuration the same. Specific steps are as follows: 1, zoo.cfg file configuration add the following configuration: authProvider.1 = org.apa ...

Original: http://hadoop.apache.org/core/docs/current/hdfs_design.html Introduction Hadoop Distributed File System (HDFS) is designed to be suitable for running in general hardware (commodity hardware) on the Distributed File system. It has a lot in common with existing Distributed file systems. At the same time, it is obvious that it differs from other distributed file systems. HDFs is a highly fault tolerant system suitable for deployment in cheap ...

1. The introduction of the Hadoop Distributed File System (HDFS) is a distributed file system designed to be used on common hardware devices. It has many similarities to existing distributed file systems, but it is quite different from these file systems. HDFS is highly fault-tolerant and is designed to be deployed on inexpensive hardware. HDFS provides high throughput for application data and applies to large dataset applications. HDFs opens up some POSIX-required interfaces that allow streaming access to file system data. HDFS was originally for AP ...

At the same time support scheduling memory and CPU resources (default only supports memory, if you want to further scheduling the CPU, you need to make some configuration), this article describes how Hadoop YARN scheduling and isolation of these resources. In YARN, resource management is done jointly by the ResourceManager and the NodeManager, where the scheduler in the ResourceManager is responsible for allocating resources and NodeManager is responsible for providing and isolating resources. ResourceM ...

As always, the issue of IT security has been a cause for concern again at the dawn of the new 2013 years. In the new year, there may be a number of high-profile large enterprises and institutions due to slow response, or do not respond to the data security threats caused by the example. Over the past few years, security threat trends are already well known to people looking for solutions in rapidly changing it areas. The rapid adoption of cloud computing, moving to virtualized infrastructure and transitioning to BYOD, has meant a waste of it to improve enterprise efficiency and to seek out corporate departments ...

When developers think of open source, they only associate "free" with nothing else. 　　Because in general, people don't pay much attention to technologies that make them free to use and have little license restrictions. Now, when companies think of open source, they immediately think of "business agility." 　　In the face of today's rapidly changing market, enterprises pay more and more attention to "business flexibility", and put it in the first place in the development of enterprises. The relevant IT industry people say, using open source technology, can quickly and effectively develop new applications, but also to save costs, which makes Xu ...

Overview Hadoop on Demand (HOD) is a system that can supply and manage independent Hadoop map/reduce and Hadoop Distributed File System (HDFS) instances on a shared cluster. It makes it easy for administrators and users to quickly build and use Hadoop. Hod is also useful for Hadoop developers and testers who can share a physical cluster through hod to test their different versions of Hadoop. Hod relies on resource Manager (RM) to assign nodes ...

Introduction to Namenode in Hadoop is like the heart of a human being, and it's important not to stop working. In the HADOOP1 era, there was only one namenode. If the Namenode data is missing or does not work, the entire cluster cannot be recovered. This is a single point in the Hadoop1 and a hadoop1 unreliable performance, as shown in Figure 1. 　　HADOOP2 solved the problem. The high reliability of HDFs in hadoop2.2.0 means that you can start 2 name ...

In addition to the "normal" file, HDFs introduces a number of specific file types (such as Sequencefile, Mapfile, Setfile, Arrayfile, and bloommapfile) that provide richer functionality and typically simplify data processing. Sequencefile provides a persistent data structure for binary key/value pairs. Here, the different instances of the key and value must represent the same Java class, but the size can be different. Similar to other Hadoop files, Sequencefil ...