Stream Length

Hadoop serialization and Writable Interface (i) introduced the Hadoop serialization, the Hadoop writable interface and how to customize your own writable class, and in this article we continue to introduce the Hadoop writable class, 　　This time we are concerned about the length of bytes occupied after the writable instance was serialized, and the composition of the sequence of bytes after the writable instance was serialized. Why to consider the byte length of the writable class large data program ...

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 ...

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 ...

Read the file & http: //www.aliyun.com/zixun/aggregation/37954.html "> nbsp; read the file internal working mechanism see below: The client calls FileSystem object (corresponding to the HDFS file system, call DistributedFileSystem object) Open () method to open the file (ie the first step in the diagram), DistributedFileSyst ...

Serialization serialization (serialization) is the process of converting a structured object into a byte stream so that it can be transmitted over a network or written to a hard disk for permanent storage, and a relative deserialization (deserialization) refers to the flow of bytes back to the structured object. In a distributed system, the process serializes objects into a byte stream, travels over the network to another process, and another process receives a stream of bytes, which, by deserializing, returns to the structured object to achieve interprocess communication. In Hadoop, Mapper,combi ...

The diversity of market demand provides market space for various storage solutions. Therefore, in the future for a considerable period of time, DVR, NVR, sdi-dvr and Fcsan, Ipsan and other storage solutions will coexist. Cloud computing and cloud storage are likely to have a huge impact on the video surveillance market over the next few years and push the video surveillance industry to a new, higher stage of development. Improve storage network performance Distributed File System SDFs (Skydistributedfilesystem) meet the new requirements of security video surveillance, solution ...

The client example uses the JQuery http://www.aliyun.com/zixun/aggregation/33906.html ">javascript Library." In this first article, we explore different reverse Ajax technologies, using downloadable examples to learn the Comet of using the streaming (streaming) method and the long polling (polling) method. Web Development has been great in the past few years ...

(1) The Apache Hadoop version introduces Apache's Open source project development process:--Trunk Branch: New features are developed on the backbone branch (trunk); 　　-Unique branch of feature: Many new features are poorly stabilized or imperfect, and the branch is merged into the backbone branch after the unique specificity of these branches is perfect; --candidate Branch: Split regularly from the backbone branch, General candidate Branch release, the branch will stop updating new features, if the candidate branch has b ...

Although the "editor's note" has been available for 9 years, the popularity of Mongodb,hamsterdb is still lacking, and it has been rated as a Non-mainstream database. Hamsterdb is an open source key value type database. However, unlike other Nosql,hamsterdb, which are single-threaded and not distributed, they are designed to be more like a column store database, while also supporting acid transactions at the Read-committed isolation level. Then compare Leveldb,hamsterdb will have any advantage, here we go ...

Hadoop version and Biosphere 1. 　　Hadoop version (1) The Apache Hadoop version introduces Apache's Open source project development process: Trunk Branch: New features are developed on the backbone branch (trunk). 　　Unique branch of attribute: Many new features are poorly stabilized or imperfect, and the branch is merged into the backbone branch after the unique specificity of these branches is perfect. Candidate Branch: Periodically split from the backbone branch, the general candidate Branch release, the branch will stop updating new features, if ...