Memcached Tip 2：Session同步

http://memcachedproviders.codeplex.com/提供的Memcached客户端支持Asp.net站点中的Session同步，其原理是接管Asp.net的Session处理，同时在后台使用数据库支持完成WEB集群的Session的同步。具体实现步骤如下：

1：数据库准备

下载完毕Memcached providers之后，在解压目录下有：

一个用于创建数据库表，一个用于创建这个provider的需要用到的存储过程。

2：配置sessionState

sessionState的配置如下，为了完整性期间，这里给出Web.config的全部配置部分，包括分布式缓存的Memcached的配置：

<?xml version="1.0"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
  <configSections>
      <section name="cacheProvider" type="MemcachedProviders.Cache.CacheProviderSection,  MemcachedProviders" allowDefinition="MachineToApplication" restartOnExternalChanges="true"/>
      <sectionGroup name="enyim.com">
        <section name="memcached" type="Enyim.Caching.Configuration.MemcachedClientSection, Enyim.Caching" />
      </sectionGroup>
      <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net"/>
  </configSections>
  <log4net>
    <!-- Define some output appenders -->
    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] 
- %message%newline" />
      </layout>
    </appender>
    <!--<threshold value="OFF" />-->
    <!-- Setup the root category, add the appenders and set the default priority -->
    <root>
      <priority value="WARN"/>
      <appender-ref ref="ConsoleAppender">
        <filter type="log4net.Filter.LevelRangeFilter">
          <levelMin value="WARN"/>
          <levelMax value="FATAL"/>
        </filter>
      </appender-ref>
    </root>
  </log4net>
  <enyim.com>
    <memcached>
      <servers>
        <!-- put your own server(s) here-->
        <add address="192.168.0.96" port="11211" />
        <!--<add address="192.168.0.101" port="11211" />-->
      </servers>
      <socketPool minPoolSize="10" maxPoolSize="100"
                  connectionTimeout="00:00:10" deadTimeout="00:02:00" />
    </memcached>
  </enyim.com>
  <cacheProvider defaultProvider="MemcachedCacheProvider">
    <providers>
      <add name="MemcachedCacheProvider"
                 type="MemcachedProviders.Cache.MemcachedCacheProvider, MemcachedProviders"
                 keySuffix="_MySuffix_" defaultExpireTime="2000"/>
    </providers>
  </cacheProvider>
  
  <connectionStrings>
    <add name="ApplicationServices"
         connectionString="Data Source=192.168.0.96;Initial Catalog=ForestFire;User Id=sa;Password=sa;"
         providerName="System.Data.SqlClient" />
  </connectionStrings>
  
  <system.web>
    
    <sessionState cookieless="false" regenerateExpiredSessionId="true" mode="Custom"
 customProvider="MemcachedSessionProvider">
      <providers>
        <add name="MemcachedSessionProvider" type="MemcachedProviders.Session.SessionStateProvider,MemcachedProviders" connectionStringName="ApplicationServices" dbType="SQL" writeExceptionsToEventLog="false"   />
      </providers>
    </sessionState>
    
    <compilation debug="true" targetFramework="4.0" />

    <authentication mode="Forms">
      <forms loginUrl="~/Account/Login.aspx" timeout="2880" />
    </authentication>

    <membership>
      <providers>
        <clear/>
        <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices"
             enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false"
             maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10"
             applicationName="/" />
      </providers>
    </membership>

    <profile>
      <providers>
        <clear/>
        <add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/"/>
      </providers>
    </profile>

    <roleManager enabled="false">
      <providers>
        <clear/>
        <add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" />
        <add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" />
      </providers>
    </roleManager>

  </system.web>

  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
  </system.webServer>
</configuration>

3：代码

代码没有任何稀奇的，和传统的Session操作一样，如下：

        protected void Page_Load(object sender, EventArgs e)
        {
            try
            {
                Session["name"] = "豆腐";
            }
            catch (Exception err)
            {
                Response.Write(err.Message);
            }
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            Label1.Text = Session["name"].ToString();
        }

全部代码下载如下：WebApplication20110817.rar