HDFS的设计目标
通过上一篇文章的介绍我们已经了解到HDFS到底是怎样的东西,以及它是怎样通过多副本机制来提供高可靠性的,我们可以发现HDFS设计目标可以总结为以下几点:
非常巨大的分布式文件系统
运行在普通廉价的硬件上
易扩展、为用户提供性能不错的文件存储服务
HDFS的架构
我们通过官网的文档来了解HDFS的基础架构(http://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-hdfs/HdfsDesign.html):
Introduction
The Hadoop Distributed File System (HDFS) is a distributed file system designed to run on commodity hardware. It has many similarities with existing distributed file systems. However, the differences from other distributed file systems are significant. HDFS is highly fault-tolerant and is designed to be deployed on low-cost hardware. HDFS provides high throughput access to application data and is suitable for applications that have large data sets. HDFS relaxes a few POSIX requirements to