Sql Server瞬态异常数

Question

我想为我的数据库调用编写一些包装代码(使用C#和Microsoft技术访问数据库),自动重试"瞬态"异常.通过瞬态,我的意思是有一个很好的机会最终会解决(对于逻辑错误,永远不会工作).我能想到的例子包括:

• 僵局
• 连接超时
• 命令超时

我曾计划使用SqlException的错误号来发现这些.例如:

List<RunStoredProcedureResultType> resultSet = null;
int limit = 3;
for (int i = 0; i < limit; ++i)
{
    bool isLast = i == limit - 1;
    try
    {
        using (var db = /* ... */)
        {
            resultSet = db.RunStoredProcedure(param1, param2).ToList();
        }
        //if it gets here it was successful
        break;
    }
    catch (SqlException ex)
    {
        if (isLast)
        {
            //3 transient errors in a row. So just kill it
            throw;
        }
        switch (ex.Number)
        {
            case 1205: //deadlock
            case -2:   //timeout (command timeout?)
            case 11:   //timeout (connection timeout?)
                // do nothing - continue the loop
                break;
            default:
                //a non-transient error. Just throw the exception on
                throw;
        }
    }
    Thread.Sleep(TimeSpan.FromSeconds(1)); //some kind of delay - might not use Sleep
}
return resultSet;

(请原谅我的任何错误 - 我刚刚写完了.我也意识到我可以很好地把它包起来......)

所以关键问题是:我应该将哪些数字视为"瞬态"(我意识到我认为瞬态可能与其他人认为瞬态不同).我在这里找到了一个很好的清单:

https://msdn.microsoft.com/en-us/library/cc645603.aspx

但它的大量和注意非常有用.有没有其他人建立一个他们用于类似的东西的列表？

UPDATE

最后,我们选择了一个"坏列表" - 如果错误是已知的"非瞬态错误"列表中的一个 - 通常是程序员错误.我已经列出了一个我们正在使用的数字列表作为答案.

Answer 1

[SqlDatabaseTransientErrorDetectionStrategy.cs]sql Azure中有一个用于临时故障处理的类.它涵盖了几乎所有类型的异常代码,可以视为瞬态代码.它也是一个完整的实现Retry strategy.

在此处添加代码段以供将来参考:

/// <summary>
/// Error codes reported by the DBNETLIB module.
/// </summary>
private enum ProcessNetLibErrorCode
{
    ZeroBytes = -3,

    Timeout = -2,
    /* Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. */

    Unknown = -1,

    InsufficientMemory = 1,

    AccessDenied = 2,

    ConnectionBusy = 3,

    ConnectionBroken = 4,

    ConnectionLimit = 5,

    ServerNotFound = 6,

    NetworkNotFound = 7,

    InsufficientResources = 8,

    NetworkBusy = 9,

    NetworkAccessDenied = 10,

    GeneralError = 11,

    IncorrectMode = 12,

    NameNotFound = 13,

    InvalidConnection = 14,

    ReadWriteError = 15,

    TooManyHandles = 16,

    ServerError = 17,

    SSLError = 18,

    EncryptionError = 19,

    EncryptionNotSupported = 20
}

还有一个switch case来检查sql异常中是否返回错误号:

switch (err.Number)
{
    // SQL Error Code: 40501
    // The service is currently busy. Retry the request after 10 seconds. Code: (reason code to be decoded).
    case ThrottlingCondition.ThrottlingErrorNumber:
        // Decode the reason code from the error message to determine the grounds for throttling.
        var condition = ThrottlingCondition.FromError(err);

        // Attach the decoded values as additional attributes to the original SQL exception.
        sqlException.Data[condition.ThrottlingMode.GetType().Name] =
            condition.ThrottlingMode.ToString();
        sqlException.Data[condition.GetType().Name] = condition;

        return true;

    // SQL Error Code: 10928
    // Resource ID: %d. The %s limit for the database is %d and has been reached.
    case 10928:
    // SQL Error Code: 10929
    // Resource ID: %d. The %s minimum guarantee is %d, maximum limit is %d and the current usage for the database is %d. 
    // However, the server is currently too busy to support requests greater than %d for this database.
    case 10929:
    // SQL Error Code: 10053
    // A transport-level error has occurred when receiving results from the server.
    // An established connection was aborted by the software in your host machine.
    case 10053:
    // SQL Error Code: 10054
    // A transport-level error has occurred when sending the request to the server. 
    // (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
    case 10054:
    // SQL Error Code: 10060
    // A network-related or instance-specific error occurred while establishing a connection to SQL Server. 
    // The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server 
    // is configured to allow remote connections. (provider: TCP Provider, error: 0 - A connection attempt failed 
    // because the connected party did not properly respond after a period of time, or established connection failed 
    // because connected host has failed to respond.)"}
    case 10060:
    // SQL Error Code: 40197
    // The service has encountered an error processing your request. Please try again.
    case 40197:
    // SQL Error Code: 40540
    // The service has encountered an error processing your request. Please try again.
    case 40540:
    // SQL Error Code: 40613
    // Database XXXX on server YYYY is not currently available. Please retry the connection later. If the problem persists, contact customer 
    // support, and provide them the session tracing ID of ZZZZZ.
    case 40613:
    // SQL Error Code: 40143
    // The service has encountered an error processing your request. Please try again.
    case 40143:
    // SQL Error Code: 233
    // The client was unable to establish a connection because of an error during connection initialization process before login. 
    // Possible causes include the following: the client tried to connect to an unsupported version of SQL Server; the server was too busy 
    // to accept new connections; or there was a resource limitation (insufficient memory or maximum allowed connections) on the server. 
    // (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
    case 233:
    // SQL Error Code: 64
    // A connection was successfully established with the server, but then an error occurred during the login process. 
    // (provider: TCP Provider, error: 0 - The specified network name is no longer available.) 
    case 64:
    // DBNETLIB Error Code: 20
    // The instance of SQL Server you attempted to connect to does not support encryption.
    case (int)ProcessNetLibErrorCode.EncryptionNotSupported:
        return true;
}

在此查看完整来源.

Answer 2

很抱歉回答我自己的问题，但如果有人仍然感兴趣，我们刚刚开始建立我们自己的错误代码列表。不理想，但我们认为这不应该经常发生。

我们选择了“坏名单”方法，而不是问题中暗示的“好名单”。到目前为止，我们拥有的 id 是：

PARAMETER_NOT_SUPPLIED = 201;
CANNOT_INSERT_NULL_INTO_NON_NULL = 515;
FOREGIN_KEY_VIOLATION = 547;
PRIMARY_KEY_VIOLATION = 2627;
MEMORY_ALLOCATION_FAILED = 4846;
ERROR_CONVERTING_NUMERIC_TO_DECIMAL = 8114; 
TOO_MANY_ARGUMENTS = 8144;
ARGUMENT_IS_NOT_A_PARAMETER = 8145;
ARGS_SUPPLIED_FOR_PROCEDURE_WITHOUT_PARAMETERS = 8146;
STRING_OR_BINARY_TRUNCATED = 8152;
INVALID_POINTER = 10006;
WRONG_NUMBER_OF_PARAMETERS = 18751;

我们注意到的另一件事是，如果连接池超时，您不会收到 SqlException - 相反，您会收到报告“超时已过期”的 InvalidOperationException。遗憾的是它不是 SqlException 但非常值得捕获。

我会尽量保持最新的任何添加。