As we all know, Java in the processing of data is relatively large, loading into memory will inevitably lead to memory overflow, while in some http://www.aliyun.com/zixun/aggregation/14345.html "> Data processing we have to deal with massive data, in doing data processing, our common means is decomposition, compression, parallel, temporary files and other methods; For example, we want to export data from a database, no matter what the database, to a file, usually Excel or ...
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 ...
Take the XX data file from the FTP host. Tens not just a concept, represents data that is equal to tens of millions or more than tens of millions of data sharing does not involve distributed collection and storage and so on. Is the processing of data on a machine, if the amount of data is very large, you can consider distributed processing, if I have this experience, will be in time to share. 1, the application of the FTP tool, 2, tens the core of the FTP key parts-the list directory to the file, as long as this piece is done, basically the performance is not too big problem. You can pass a ...
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 ...
Aiming at the problem of low storage efficiency of small and medium files in cloud storage system based on HDFS, the paper designs a scheme of small and medium file in cloud storage System with sequential file technology. Using multidimensional attribute decision theory, the scheme by combining the indexes of reading file time, merging file time and saving memory space, we get the best way of merging small files, and can achieve the balance between the time consumed and the memory space saved; The system load forecasting algorithm based on AHP is designed to predict the system load. To achieve the goal of load balancing, the use of sequential file technology to merge small files. Experimental results show that ...
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 ...
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 ...
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 ...
Sc++a Java runtime consists of core and extension. Core is essentially a wiring engine for multiple VMs. The engine uses the IOC (control reversal) and Di (Dependency injection) principles to connect components. Core core is simple and limited in performance. It connects functional units together and provides SPI mechanisms that can interact with extension. Such features as service discovery, reliability, and support for transport protocols are done through extension. Extension ...
Windows Azure provides a highly scalable storage mechanism for storing structured and unstructured data, known as Windows Azure Storage. Windows Azure Storage provides a development interface for the REST-based Web Service. This means that any programming language under any platform can access Windows Azure Storage by this development interface as long as it supports HTTP communication protocols. Of course...
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