EF 4.0：保存更改重试逻辑

Question

我想为所有实体SaveChanges方法调用实施应用程序范围重试系统。

技术：
实体框架4.0
.NET 4.0

namespace Sample.Data.Store.Entities { 
    public partial class StoreDB 
    { 
     public override int SaveChanges(System.Data.Objects.SaveOptions options) 
     {    
      for (Int32 attempt = 1; ;) 
      { 

       try 
       { 
        return base.SaveChanges(options); 
       } 
       catch (SqlException sqlException) 
       { 
        // Increment Trys 
        attempt++; 

        // Find Maximum Trys 
        Int32 maxRetryCount = 5; 

        // Throw Error if we have reach the maximum number of retries 
        if (attempt == maxRetryCount) 
         throw; 

        // Determine if we should retry or abort. 
        if (!RetryLitmus(sqlException)) 
         throw; 
        else 
         Thread.Sleep(ConnectionRetryWaitSeconds(attempt)); 
       } 
      } 
     } 

     static Int32 ConnectionRetryWaitSeconds(Int32 attempt) 
     { 
      Int32 connectionRetryWaitSeconds = 2000; 

      // Backoff Throttling 
      connectionRetryWaitSeconds = connectionRetryWaitSeconds * 
       (Int32)Math.Pow(2, attempt); 

      return (connectionRetryWaitSeconds); 
     } 



     /// <summary> 
     /// Determine from the exception if the execution 
     /// of the connection should Be attempted again 
     /// </summary> 
     /// <param name="exception">Generic Exception</param> 
     /// <returns>True if a a retry is needed, false if not</returns> 
     static Boolean RetryLitmus(SqlException sqlException) 
     { 
     switch (sqlException.Number) 
      { 
       // The service has encountered an error 
       // processing your request. Please try again. 
       // Error code %d. 
       case 40197: 
       // The service is currently busy. Retry 
       // the request after 10 seconds. Code: %d. 
       case 40501: 
       //A transport-level error has occurred when 
       // receiving results from the server. (provider: 
       // TCP Provider, error: 0 - An established connection 
       // was aborted by the software in your host machine.) 
       case 10053: 
        return (true); 
      } 

      return (false); 
     } 
    } 
} 

问题：

我怎么可以运行StoreDB.SaveChanges到一个新的DB背景下重试错误发生后？ 与Detach/Attach类似的东西可能会派上用场。

在此先感谢！ Bart

Answer 1

查看SQL Azure的瞬态故障处理框架，here。这是非常通用的，并且很容易修改以包含后端的重试逻辑。