OpenStack：构建公有云和私有云的开源软件

什么是OpenStack?

       OpenStack 提供了一个构建公有云和私有云的开源软件. OpenStack既是一个社区,也是一个项目和一个开源软件,它帮助组织运行为虚拟计算或存储服务的云. OpenStack旗下包含了一组由社区维护开源项目, 它们是OpenStack Compute(代号为Nova), OpenStack Object(代号为Swift)和OpenStack Image Service(代号为Glance).  OpenStack提供了一个部署云的操作平台或工具集.

       一旦云计算的概念变得清晰,OpenStack也就更容易理解. 我们任务是: 为公有云,私有云,也为大云和小云提供一个可扩展的,灵活的云计算.  而任务的核心有两个基本要求: 云的实现必需简单和大规模扩展.

概念架构:

       OpenStack项目作为一个整体被设计成”提供一个大规模可伸缩的云操作系统”. 为了实现这一目标, 每个组件被设计为协同工作,以提供一个完整的基础设施服务(IaaS). 通过公共应用程序编程接口(APIs)提供的服务, 使得整合非常的方便. 这些API允许每个服务使用其它的服务的同时, 它也允许实施者转出任何服务,只要他们持有相应的API. 这些(大部分)API和提供给终端用户使用的API是相同的.

       从概念上讲,服务之间的关系如下图所示:

• Horizon为其它OpenStack服务提供web前端
• Nova存储和检索虚拟磁盘(映像)和Glance中相关的元数据

• Glance能够在Swift存储实际的虚拟磁盘文件
• 所有的服务最终都通过Keystone进行认证
  

       ,它假设了实施者以最常见的配置在使用所有的服务. 它也只显示了”操作者”一端的云, 它并没有显示出消费者如何实际使用它. 例如, 许多计算机用户都会经常使用对象存储服务.

其它一些资料:

1. OpenStack主页:openstack.org

2. OpenStack与Hadoop的区别
OpenStack是IaaS(基础设施即服务)‎软件,它旨在实现云操作系统,让任何人可以建立与提供云端计算服务.
Hadoop是一个重量级的分布式处理开源框架,侧重于hdfs云存储与mapreduce云数据分析等方面.



PS：从Word粘贴过来，格式各种有问题
文档为：

附原文：

OpenStack

Open source software for building private and public cloud

·What is OpenStack？

     OpenStack offers open source software to build public and private clouds. OpenStack is a community and a project as well as open source software to help organizations run clouds for virtual computing or storage. OpenStack contains a collection of open source projects that are community-maintained including OpenStack Compute (code-named Nova), OpenStack Object Storage (code-named Swift), and OpenStack Image Service (code-named Glance). OpenStack provides an operating platform, or toolkit, for orchestrating clouds.

·Conceptual Architecture：

     The OpenStack project as a whole is designed to "deliver(ing) a massively scalable cloud operating system." To achieve this, each of the constituent services are designed to work together to provide a complete Infrastructure as a Service (IaaS). This integration is facilitated through public application programming interfaces (APIs) that each service offers (and in turn can consume). While these APIs allow each of the services to use another service, it also allows an implementer to switch out any service as long as they maintain the API. These are (mostly) the same APIs that are available to end users of the cloud.



     ·Horizon provides a web front end to the other OpenStack services
     ·Nova stores and retrieves virtual disks ("images") and associated metadata in Glance
     ·Glance can store the actual virtual disk files in Swift
     ·All the services (will eventually) authenticate with Keystone

     This is a stylized and simplified view of the architecture, assuming that the implementer is using all of the services together in the most common configuration. It also only shows the "operator" side of the cloud -- it does not picture how consumers of the cloud may actually use it. For example, many compute users will use object storage heavily (and directly).