System.Data.Entity.Infrastructure.CommitFailedException：C# 多线程和 SQL Server 2012

Question

我们有一个 C# 多线程（100 个线程）程序，它从数据库中读取记录，每个线程获取一条记录（每个线程一个实体框架连接）并更新单个数据库表。

前几分钟（5 分钟）程序正常运行，然后突然所有线程开始抛出以下错误消息.. 约 1 分钟后，一切都会恢复正常阶段.. 我认为 SQL Server 也越来越好了单个数据库表的许多锁（可能正在尝试获取该表上的表锁）或与单个数据库的连接过多并关闭所有连接..

我无法调试这个，有人可以帮助我获取以下信息，

1. SQL Server 2012 在哪里存储其日志？

2. 我们可以提高日志级别以查看为什么在保存数据库实体时会抛出异常

3. 如何获取每个表的锁数，DB 获取的不同类型的锁（表锁、页锁、行锁数等）

调试此问题的任何其他指针。

仅供参考，我在从这个 cmd 得到的 sqlerror 日志中没有发现任何有用的东西：

SELECT SERVERPROPERTY('ErrorLogFileName')

这是异常的堆栈跟踪：

System.Data.Entity.Infrastructure.CommitFailedException: An error was reported while committing a database transaction but it could not be determined whether the transaction succeeded or failed on the database server. See the inner exception and http://go.microsoft.com/fwlink/?LinkId=313468 for more information.

System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
System.ComponentModel.Win32Exception: The wait operation timed out
at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action1 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.TdsParser.TdsExecuteTransactionManagerRequest(Byte[] buffer, TransactionManagerRequestType request, String transactionName, TransactionManagerIsolationLevel isoLevel, Int32 timeout, SqlInternalTransaction transaction, TdsParserStateObject stateObj, Boolean isDelegateControlRequest)
  at System.Data.SqlClient.SqlInternalConnectionTds.ExecuteTransactionYukon(TransactionRequest transactionRequest, String transactionName, IsolationLevel iso, SqlInternalTransaction internalTransaction, Boolean isDelegateControlRequest)
  at System.Data.SqlClient.SqlInternalConnectionTds.ExecuteTransaction(TransactionRequest transactionRequest, String name, IsolationLevel iso, SqlInternalTransaction internalTransaction, Boolean isDelegateControlRequest)
  at System.Data.SqlClient.SqlInternalTransaction.Commit()
  at System.Data.SqlClient.SqlTransaction.Commit()
  at System.Data.Entity.Infrastructure.Interception.DbTransactionDispatcher.<Commit>b__c(DbTransaction t, DbTransactionInterceptionContext c)
  at System.Data.Entity.Infrastructure.Interception.InternalDispatcher1.Dispatch[TTarget,TInterceptionContext](TTarget target, Action2 operation, TInterceptionContext interceptionContext, Action3 executing, Action`3 executed)
--- End of inner exception stack trace ---
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher1.Dispatch[TTarget,TInterceptionContext](TTarget target, Action2 operation, TInterceptionContext interceptionContext, Action3 executing, Action3 executed)
at System.Data.Entity.Infrastructure.Interception.DbTransactionDispatcher.Commit(DbTransaction transaction, DbInterceptionContext interceptionContext)
at System.Data.Entity.Core.EntityClient.EntityTransaction.Commit()
at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
  at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction)
  at System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClass2a.<SaveChangesInternal>b__27()
  at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func1 operation)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(SaveOptions options, Boolean executeInExistingTransaction)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options)
at System.Data.Entity.Internal.InternalContext.SaveChanges()
at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
at System.Data.Entity.DbContext.SaveChanges()

Answer 1

看起来像是在行动中阻止。

您应该尝试使用sp_WhoIsActive或扩展事件会话等工具来监视阻塞。

如果您想使用扩展事件，有一个名为ExtendedTSQLCollector 的工具可以帮助您自动监视和收集所需的事件。我写了一篇关于如何使用它来监视阻塞和死锁的博客文章。您可以在这里找到它：使用扩展 T-SQL 收集器监控阻塞和死锁