如何调试，SQL Server异常，操作完成之前超时时间或服务器没有响应

Question

我正在使用SqlBulkCopy将一个大文件（〜25 GB，4亿行）加载到SQL Server 2014中。

我的批量复制大小为1万行，超时为1小时。 整个文件在一个事务中，因为我想存储整个文件或在出现故障时回滚。 我在此表上有3个索引（一个唯一的聚集索引，另外两个是非聚集索引）。

有时我会遇到以下异常：

System.Data.SqlClient.SqlException（0x80131904）：超时已过期。 在操作完成之前超时或服务器没有响应。

System.ComponentModel.Win32Exception（0x80004005）：等待操作超时

在System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning（ 1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error) at System.Data.SqlClient.TdsParserStateObject.ReadSniSyncOverAsync() at System.Data.SqlClient.TdsParserStateObject.TryReadNetworkPacket() at System.Data.SqlClient.TdsParserStateObject.TryPrepareBuffer() at System.Data.SqlClient.TdsParserStateObject.TryReadByte(Byte& value) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlBulkCopy.RunParser(BulkCopySimpleResultSet bulkCopyHandler) at System.Data.SqlClient.SqlBulkCopy.CopyBatchesAsyncContinuedOnSuccess(BulkCopySimpleResultSet internalResults, String updateBulkCommandText, CancellationToken cts, TaskCompletionSource异常，布尔breakConnection，操作1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error) at System.Data.SqlClient.TdsParserStateObject.ReadSniSyncOverAsync() at System.Data.SqlClient.TdsParserStateObject.TryReadNetworkPacket() at System.Data.SqlClient.TdsParserStateObject.TryPrepareBuffer() at System.Data.SqlClient.TdsParserStateObject.TryReadByte(Byte& value) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlBulkCopy.RunParser(BulkCopySimpleResultSet bulkCopyHandler) at System.Data.SqlClient.SqlBulkCopy.CopyBatchesAsyncContinuedOnSuccess(BulkCopySimpleResultSet internalResults, String updateBulkCommandText, CancellationToken cts, TaskCompletionSource 1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error) at System.Data.SqlClient.TdsParserStateObject.ReadSniSyncOverAsync() at System.Data.SqlClient.TdsParserStateObject.TryReadNetworkPacket() at System.Data.SqlClient.TdsParserStateObject.TryPrepareBuffer() at System.Data.SqlClient.TdsParserStateObject.TryReadByte(Byte& value) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlBulkCopy.RunParser(BulkCopySimpleResultSet bulkCopyHandler) at System.Data.SqlClient.SqlBulkCopy.CopyBatchesAsyncContinuedOnSuccess(BulkCopySimpleResultSet internalResults, String updateBulkCommandText, CancellationToken cts, TaskCompletionSource 。 SqlBulkCopy.CopyBatchesAsyncContinued（BulkCopySimpleResultSet internalResults，字符串updateBulkCommandText，CancellationToken cts，TaskCompletionSource 1 source) at System.Data.SqlClient.SqlBulkCopy.CopyBatchesAsync(BulkCopySimpleResultSet internalResults, String updateBulkCommandText, CancellationToken cts, TaskCompletionSource 1。 1 source) at System.Data.SqlClient.SqlBulkCopy.WriteToServerInternalRestAsync(CancellationToken cts, TaskCompletionSource 1源）处的WriteToServerInternalRestContinuedAsync（BulkCopySimpleResultSet internalResults，CancellationToken cts，TaskCompletionSource 1 source) at System.Data.SqlClient.SqlBulkCopy.WriteToServerInternalRestAsync(CancellationToken cts, TaskCompletionSource System.Data.SqlClient.SqlBulkCopy.WriteRowSourceToServerAsync（Int32 columnCount，CancellationToken ctoken）处的em.Data.SqlClient.SqlBulkCopy.WriteToServerInternalAsync（CancellationToken ctoken）在System.Data.SqlClient.SqlBulkCopy.WriteToServer（IDataReader reader）

在发生异常的情况下，我会回滚整个事务，但是随后在尝试回滚时又看到了一个异常。 我不明白为什么SqlTransaction不能处于可用状态，因为我的代码没有在其他任何地方关闭连接/事务。

System.InvalidOperationException：该SqlTransaction已完成； 它不再可用。

我已经进行了某种程度的调试，在SSMS中，我看到有一个未完成的事务

select @@TRANCOUNT  ==> this gives "0" (I didn't understand why)

dbcc opentran ==> this gives me a open transaction

Oldest active transaction:
    SPID (server process ID): 58
    UID (user ID) : -1
    Name          : user_transaction
    LSN           : (159:2843368:1)
    Start time    : Dec 30 2014 11:20:13:903PM
    SID           : 0x0105000000000005150000005d28f57fd53ad8354354e02ae9881a00
DBCC execution completed. If DBCC printed error messages, contact your system administrator.

然后使用此SQL脚本，我发现它卡在了网上

insert bulk dbo.#mytablename#

在状态为运行的情况下，时间戳与引发异常的时间完全匹配-1小时（批量复制超时）。 但是我不知道为什么SQL Server会卡在这里以及为什么要花费更多时间。 有办法进一步调试吗？

SELECT 
   r.[session_id],
   c.[client_net_address],
   s.[host_name],
   c.[connect_time],
   [request_start_time] = s.[last_request_start_time],
   [current_time] = CURRENT_TIMESTAMP,
   r.[percent_complete],
   [estimated_finish_time] = DATEADD
       (
           MILLISECOND,
           r.[estimated_completion_time], 
           CURRENT_TIMESTAMP
       ),
   current_command = SUBSTRING
       (
           t.[text],
           r.[statement_start_offset]/2,
           COALESCE(NULLIF(r.[statement_end_offset], -1)/2, 2147483647)
       ),
   module = COALESCE(QUOTENAME(OBJECT_SCHEMA_NAME(t.[objectid], t.[dbid])) 
       + '.' + QUOTENAME(OBJECT_NAME(t.[objectid], t.[dbid])), '<ad hoc>'),
   [status] = UPPER(s.[status])
 FROM
     sys.dm_exec_connections AS c
 INNER JOIN
     sys.dm_exec_sessions AS s
     ON c.session_id = s.session_id
 LEFT OUTER JOIN
     sys.dm_exec_requests AS r
     ON r.[session_id] = s.[session_id]
 OUTER APPLY
     sys.dm_exec_sql_text(r.[sql_handle]) AS t
 WHERE
     c.session_id = 58;

Answer 1

之所以超时是因为您的大量加载需要一个多小时才能完成 。 根据MSDN ，超时设置是指

操作在超时之前完成的秒数。

一个25GB的文件可能需要一个多小时才能加载到数据库中，所以为什么不尝试设置更高的超时值以便它有足够的时间来完成是有道理的？