优势

• 可测量性
  Session/Application状态对象保存在几个状态服务器上，并允许添加至所需数量的状态服务器。使用多点传送请求同时不会出现多个点对点的数据传输。
• 可靠性
  每个状态对象都被复制到不同的状态服务器上。
• 性能
  所有状态对象都存储在内存中，消除了I/O瓶颈。
• 易管理
  简单的安装，集中的事件日志，明确的升级方法，嵌入一个图形化的监视应用程序让你明确了解所有运行StateMirror的状态服务器以及web服务器。

组件
StateMirror安装包包含以下组件：

• StateMirror服务器
  StateMirror体系的核心：一个中心服务器用于存储状态对象。一个web站点可以使用任意数量的状态服务器(取决于工作量)。
• StateMirror客户端
  一个植入ASP.NET工作进程用于状态管理的.NET程序集。StateMirror客户端与所有激活的StateMirror服务器保持连接同时选择一个合适的服务器来读写session/application状态对象。多点传送请求被用于状态服务器的状态请求以及保存。
• StateMirror浏览器
  一个图形化的应用程序用于提供所有激活的StateMirror服务器和客户端的最新统计数据。同时也提供一些基本的管理功能比如启动或停止一个服务以及修改一一些设置等。

Benefits

• Scalability
  Session/Application state objects are stored on several state servers, enabling you to add as many state servers you need. Multicast requests are used and no multiple peer-to-peer data transfers occur.
• Reliability
  Every state object has several copies on different state servers.
• Performance
  All state objects are stored in memory, eliminating the I/O bottleneck.
• Manageability
  Easy installation, centralized event logging, clear upgrade path, plus a GUI monitor application that keeps track of all running StateMirror state servers and web servers in the farm.

Components
StateMirror installation package contains the following components:

• StateMirror Server
  The heart of the StateMirror architecture: an NT service that stores state objects. A web farm can use any number of state servers, depending on the workload.
• State Mirror Client
  A .NET assembly that hooks into the ASP.NET working process and takes care of state management functions. StateMirror Client keeps in touch with all active StateMirror Servers and chooses the right server for reading and writing session/application state object. Multicast requests are used to request state info from state servers and to save state object to state servers.
• StateMirror Explorer
  A GUI application that provides up-to-date statistics about all active StateMirror Servers and Clients. It can also perform some basic administrative functions like starting or stopping a server and changing some of its settings.