(39)Avoid using session state
招数39：
避免使用会话状态
Where possible, you should try and avoid using session state. Whilst using one web server, performance is usually not a problem. This changes as soon as you need to scale to multiple servers, as different, and usually slower, techniques need to be used.
如果可能，你应该试着避免使用会话状态。在使用一台Web服务器时，性能通常不是一个问题。一旦你需要扩展到多态服务器就会变的不同，比平时慢，而且需要使用技巧。