memcached缓存机制+微软缓存机制使用详解

1、 why Memcached

1.1 一台web服务器上，iis接收的请求数是有限的，当访问量超大的时候，网站访问就会遇到瓶颈了，处理方式就是运用多了服务器把请求数分流（集群），对外公布的就一个公共的ip。

1.2 当数据访问量有10w时候，通过3台服务器分流请求，每台即承担了3.3w个请求，当用户登录的时候，如何共享登录信息就成为需要解决的问题（如把登录信息放到数据库中，性能会很差），这就是分布式缓存的运用场景。

2、 Memcached基本介绍

2.1 key最大：255字节，value最大：1m，{key:key1,value:123}

3、Windows下使用Memcache

3.1 下载memcache：www.code.jellycan.com/Memcache

3.2 安装服务：cmd---Memcached.exe –d install

3.3 启动服务：cmd---Memcached.exe –d start (restart 重启，stop关闭)

3.4 检查服务是否启动：连接到Memcache控制台：telnet 127.0.0.1 11211，回车，输入命令：stats 检查当前服务状态。

3.5 卸载Memcached.exe –d uninstall

遇到问题：如无法启动此程序，解决方法：下载MSVCR71.dll，安装上即可。

3.6 增删改查输命令方式

3.6.1 add keyname 0 0 5 回车 //第一个0是一个数字，第二个是过期时间，单位秒，0表示不限期，5表示value长度，如keyname存在，则不做操作

12345 //value内容

3.6.2 get keyname //得到相应的value的值

3.6.3 delete keyname //删除

3.6.4 set keyname 0 0 5 回车 //如果没有则添加，如有就更新

12345

3、 c#下操作memcache

4、 微软缓存方式

demo

业务逻辑层：

接口：ICacheManager

1 public interface ICacheManager2     {3         object Get(string key);4         void Set(string key, object value);5         void Set(string key, object value, int timeout);6         void Remove(string key);7         void RemoveAll();8     }

CacheFactory类：

 1 public class CacheFactory 2     { 3         PRivate static ICacheManager _instance = null; 4         private static object m_LockObj = new object(); 5         private CacheFactory() { } 6         static CacheFactory() 7         { 8             GetInstance(); 9         }10         public static ICacheManager GetInstance()11         {12             if (_instance == null)13             {14                 lock (m_LockObj)15                 {16                     if (_instance == null)17                     {18                         string cacheType = ConfigurationSettings.AppSettings["CacheType"];19                         if (cacheType == "MemCacheManager")20                             _instance = new MemCachedManager();21                         else22                             _instance = new MsCacheManager();23                     }24                 }25             }26             return _instance;27         }28     }

MemCachedManager类：

 1 public class MemCachedManager: ICacheManager 2     { 3         private MemcachedClient m_CacheManager; 4  5         public MemCachedManager() 6         { 7             m_CacheManager = MemcachedClient.GetInstance("CachePS"); 8         } 9         public void Set(string key, object value)10         {11             m_CacheManager.Set(key, value);12         }13         public void Set(string key, object value, int timeout)14         {15             m_CacheManager.Set(key, value, DateTime.Now.AddMinutes(timeout));16         }17         public object Get(string key)18         {19             return m_CacheManager.Get(key);20         }21         public void Remove(string key)22         {23             m_CacheManager.Delete(key);24         }25         public void RemoveAll()26         {27             m_CacheManager.FlushAll();28         }29     }

MsCacheManager类：

 1 public class MsCacheManager : ICacheManager 2     { 3         private BaseCacheDAL m_CacheManager; 4  5         public MsCacheManager() 6         { 7             m_CacheManager = new BaseCacheDAL("CachePS"); 8         } 9 10         public object Get(string key)11         {12             return m_CacheManager.GetCache(key);13         }14 15         public void Set(string key, object value)16         {17             m_CacheManager.SetCache(key, value, 0);18         }19 20         public void Set(string key, object value, int timeout)21         {22             m_CacheManager.SetCache(key, value, timeout);23         }24 25         public void Remove(string key)26         {27             m_CacheManager.Remove(key);28         }29 30         public void RemoveAll()31         {32             m_CacheManager.RemoveAll();33         }34     }

调用：

 1  public static DataTable GetCarPList(int UserId) 2         { 3             DataTable dt; 4             dt = cacheManger.Get(CacheKey.GetCarPList_Key()) as DataTable; 5             if (dt == null) 6             { 7                 string sql = string.Format("select C.CarId,C.ProId,C.UserId,C.BuyNumber,P.ProName,P.Price,P.ProImage,P.Stock  from Car C inner join Product P on C.ProId=P.ProId where C.UserId={0}", UserId); 8                 dt = SqlHelper.ExecuteDataTable(com.Model.Base.DataBaseEnum.ruanmou, sql, CommandType.Text, null); 9                 cacheManger.Set(CacheKey.GetCarPList_Key(), dt, 60);10             }11             return dt;12         }

web.config重要节点配置：

1 <appSettings>2     <add key="CacheType" value="MsCacheManager"/>3     <!--<add key="CacheType" value="MemCacheManager"/>-->4   </appSettings>

1 <configSections>2     <section name="dataConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings, Microsoft.Practices.EnterpriseLibrary.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>3     <section name="cachingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Caching.Configuration.CacheManagerSettings, Microsoft.Practices.EnterpriseLibrary.Caching, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>4     <section name="enterpriseLibrary.ConfigurationSource" type="Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ConfigurationSourceSection, Microsoft.Practices.EnterpriseLibrary.Common, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>5     <section name="memcachedgarden" type="System.Configuration.NameValueSectionHandler"/>6   </configSections>

 1 <cachingConfiguration defaultCacheManager="CachePS"> 2     <cacheManagers> 3       <add expirationPollFrequencyInSeconds="120" maximumElementsInCacheBeforeScavenging="1000" numberToRemoveWhenScavenging="10" backingStoreName="Null Storage" type="Microsoft.Practices.EnterpriseLibrary.Caching.CacheManager, Microsoft.Practices.EnterpriseLibrary.Caching, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" name="CachePS"/> 4     </cacheManagers> 5     <backingStores> 6       <add encryptionProviderName="" type="Microsoft.Practices.EnterpriseLibrary.Caching.BackingStoreImplementations.NullBackingStore, Microsoft.Practices.EnterpriseLibrary.Caching, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" name="Null Storage"/> 7     </backingStores> 8   </cachingConfiguration> 9   <enterpriseLibrary.ConfigurationSource selectedSource="System Configuration Source">10     <sources>11       <add name="System Configuration Source" type="Microsoft.Practices.EnterpriseLibrary.Common.Configuration.SystemConfigurationSource, Microsoft.Practices.EnterpriseLibrary.Common, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>12     </sources>13   </enterpriseLibrary.ConfigurationSource>14   <memcachedgarden>15     <add key="CachePS" value="127.0.0.1:11211"/>16   </memcachedgarden>