无法查询Active Directory，远程过程调用失败中间失败

Question

在.Net 4.5 MVC Web应用程序中我们正在使用基于AD的角色，为此我们依赖于此          System.Web.Security.Roles.GetRolesForUser(HttpContext.Current.Request.LogonUserIdentity.Name)

但是看看elmah日志，我们发现这部分请求并非意外失败

内部堆栈跟踪

System.Configuration.Provider.ProviderException: Unable to query Active Directory. ---> System.DirectoryServices.ActiveDirectory.ActiveDirectoryServerDownException: The remote procedure call failed.

 at System.DirectoryServices.ActiveDirectory.Utils.GetDSHandle(String domainControllerName, String domainName, IntPtr authIdentity, LoadLibrarySafeHandle libHandle)
   at System.DirectoryServices.ActiveDirectory.DomainController.GetDSHandle()
   at System.DirectoryServices.ActiveDirectory.DomainController.GetDomainControllerInfo()
   at System.DirectoryServices.ActiveDirectory.DomainController.get_SiteName()
   at System.DirectoryServices.AccountManagement.ADStoreCtx.GetGroupsMemberOf(Principal p)
   at System.DirectoryServices.AccountManagement.Principal.GetGroupsHelper()
   at App.AppRoleProvider.GetRolesForUser(String username)