This article is my second time reading Hadoop 0.20.2 notes, encountered many problems in the reading process, and ultimately through a variety of ways to solve most of the. Hadoop the whole system is well designed, the source code is worth learning distributed students read, will be all notes one by one post, hope to facilitate reading Hadoop source code, less detours. 1 serialization core Technology The objectwritable in 0.20.2 version Hadoop supports the following types of data format serialization: Data type examples say ...
The release of the Java version of almost all platforms involves all aspects of the Java language itself and the JVM. So for Java 7, from the JSR draft, we get the high-level goal of Java 7: Compatibility--Any program that runs on previous versions must be able to run in Java SE 7 without making any changes; development efficiency--improve development efficiency, minimal learning curve; performance--New parallel API Interface, introduces a real asynchronous I/O AP ...
Fastinfoset as a standard XML serialization means, the XML on the basis of the compression to achieve excellent support, but the lack of direct reading tools, the user caused a certain difficulty, the use of notepad++ plug-in function and Java JNI technology, combining the characteristics of both Directly to the Fastinfoset file in the notepad++ open, to solve the user two times the trouble of editing, but also fully use notepad++ to edit the XML file ...
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 ...
Hive is a very open system, many of which support user customization, including: File format: Text file,sequence file in memory format: Java integer/string, Hadoop intwritable/text User-supplied Map/reduce script: In any language, use Stdin/stdout to transmit data user-defined functions: Substr, Trim, 1–1 user-defined poly ...
HBase is a distributed, column-oriented, open source database based on Google's article "Bigtable: A Distributed Storage System for Structured Data" by Fay Chang. Just as Bigtable takes advantage of the distributed data storage provided by Google's File System, HBase provides Bigtable-like capabilities over Hadoop. HBase Implements Bigtable Papers on Columns ...
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 ...
Xmemcached is a high-performance extensible memcached client based on Java NIO implementations. is actually based on my implementation of a NIO framework based on YAN4J (currently based on yanf4j 0.61-http://www.aliyun.com/zixun/aggregation/11220.html ">snapshot) , the serialization mechanism uses Spymemcached's transcoder and does some ...
The greatest fascination with large data is the new business value that comes from technical analysis and excavation. SQL on Hadoop is a critical direction. CSDN Cloud specifically invited Liang to write this article, to the 7 of the latest technology to do in-depth elaboration. The article is longer, but I believe there must be a harvest. December 5, 2013-6th, "application-driven architecture and technology" as the theme of the seventh session of China Large Data technology conference (DA data Marvell Conference 2013,BDTC 2013) before the meeting, ...
& http: //www.aliyun.com/zixun/aggregation/37954.html "> The ApacheSqoop (SQL-to-Hadoop) project is designed to facilitate efficient big data exchange between RDBMS and Hadoop. Users can access Sqoop's With help, it is easy to import data from relational databases into Hadoop and its related systems (such as HBase and Hive); at the same time ...
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