回滚事务时出现异常 - 连接已关闭？
Exceptions when rolling back a transaction - connection already closed?
使用 Entity Framework 6.0.0，我在关闭交易时看到异常。
我们一直在对 table 进行并发更改时遇到问题，所以我将其包装在一个事务中，现在我在回滚时遇到异常。
代码：
public LockInfo getSharedLock(string jobid)
{
using (var myDbContext = new MyDbContext())
{
using (var transaction = myDbContext.Database.BeginTransaction())
{
try
{
this.logger.log("Attempting to get shared lock for {0}", jobid);
var mylocks =
myDbContext.joblocks.Where(j => j.customerid == this.userContext.customerid)
.Where(j => j.jobid == jobid)
.Where(j => j.operatorid == this.userContext.operatorid);
var exclusiveLock = mylocks.FirstOrDefault(
j => j.lockstatus == LockInfo.LockState.Exclusive);
if (exclusiveLock != null)
{
this.logger.log("{0} already had exclusive lock, ignoring", jobid);
return LockInfo.populate(exclusiveLock);
}
var sharedLock = mylocks.FirstOrDefault(
j => j.lockstatus == LockInfo.LockState.Shared);
if (sharedLock != null)
{
this.logger.log("{0} already had shared lock, ignoring", jobid));
sharedLock.lockdt = DateTime.Now;
myDbContext.SaveChanges();
return LockInfo.populate(sharedLock);
}
var joblock = new joblock
{
customerid = this.userContext.customerid,
operatorid = this.userContext.operatorid,
jobid = jobid,
lockstatus = LockInfo.LockState.Shared,
sharedLock.lockdt = DateTime.Now
};
myDbContext.joblocks.Add(joblock);
myDbContext.SaveChanges();
transaction.Commit();
this.logger.log("Obtained shared lock for {0}", jobid);
return LockInfo.populate(joblock);
}
catch (Exception ex)
{
transaction.Rollback();
this.logger.logException(ex, "Exception in getSharedLock(\"{0}\")", jobid);
throw;
}
}
}
}
您可以在上面的代码中看到日志记录。我们也在数据库中启用了日志记录。日志跟踪：
===================
NORMAL TicketLockController.getLock("AK2015818002WL")
===================
SQL Opened connection at 9/22/2015 2:47:49 PM -05:00
===================
SQL Started transaction at 9/22/2015 2:47:49 PM -05:00
===================
NORMAL Attempting to get shared lock for AK2015818002WL
===================
SQL SELECT TOP (1) [Extent1].[customerid] AS [customerid]
,[Extent1].[jobid] AS [jobid]
,[Extent1].[lockdtdate] AS [lockdtdate]
,[Extent1].[lockdttime] AS [lockdttime]
,[Extent1].[operatorid] AS [operatorid]
,[Extent1].[lockstatus] AS [lockstatus]
,[Extent1].[changes] AS [changes]
FROM [dbo].[joblock] AS [Extent1]
WHERE ([Extent1].[customerid] = 'TESTTK')
AND ([Extent1].[jobid] = 'AK2015818002WL')
AND ([Extent1].[operatorid] = 'ADMIN')
AND (N'Exclusive' = [Extent1].[lockstatus])
===================
SQL SELECT TOP (1) [Extent1].[customerid] AS [customerid]
,[Extent1].[jobid] AS [jobid]
,[Extent1].[lockdtdate] AS [lockdtdate]
,[Extent1].[lockdttime] AS [lockdttime]
,[Extent1].[operatorid] AS [operatorid]
,[Extent1].[lockstatus] AS [lockstatus]
,[Extent1].[changes] AS [changes]
FROM [dbo].[joblock] AS [Extent1]
WHERE ([Extent1].[customerid] = 'TESTTK')
AND ([Extent1].[jobid] = 'AK2015818002WL')
AND ([Extent1].[operatorid] = 'ADMIN')
AND (N'Shared' = [Extent1].[lockstatus])
===================
SQL INSERT [dbo].[joblock] (
[customerid]
,[jobid]
,[lockdtdate]
,[lockdttime]
,[operatorid]
,[lockstatus]
,[changes]
)
VALUES (
@0
,@1
,@2
,@3
,@4
,@5
,NULL
)
===================
SQL Closed connection at 9/22/2015 2:47:50 PM -05:00
===================
EXCEPTION Unhandled exception caught: The underlying provider failed on Rollback.
===================
EXCEPTION Inner Exception: Value cannot be null.
Parameter name: connection
两次选择都成功了，然后由于某种原因插入失败了。抛出异常，由于某种原因，连接在 Rollback() 执行之前关闭。
知道我做错了什么吗？
==== 添加堆栈跟踪 ====
外部异常的堆栈跟踪：
at System.Data.Entity.Core.EntityClient.EntityTransaction.Rollback()
at korterra.kt_api.Shared.TicketLockWrangler.getSharedLock(String jobid)
at korterra.kt_ws.ApiControllers.Shared.TicketLockController.getSharedLock(TicketLockDTO ticketLockDTO)
at lambda_method(Closure , Object , Object[] )
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Tracing.ITraceWriterExtensions.<TraceBeginEndAsyncCore>d__18`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Tracing.ITraceWriterExtensions.<TraceBeginEndAsyncCore>d__18`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Filters.AuthorizationFilterAttribute.<ExecuteAuthorizationFilterAsyncCore>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()
内部异常的堆栈跟踪：
at System.Data.Entity.Utilities.Check.NotNull[T](T value, String parameterName)
at System.Data.Entity.Infrastructure.Interception.DbTransactionInterceptionContext.WithConnection(DbConnection connection)
at System.Data.Entity.Infrastructure.Interception.DbTransactionDispatcher.Rollback(DbTransaction transaction, DbInterceptionContext interceptionContext)
at System.Data.Entity.Core.EntityClient.EntityTransaction.Rollback()
经过讨论，我开始在尝试回滚之前记录异常 - 这揭示了错误。
交易陷入僵局：
Exception in getSharedLock("ticketnumber123456"): An error occurred while updating the entries. See the inner exception for details.
Inner Exception: An error occurred while updating the entries. See the inner exception for details.
Inner Exception: Transaction (Process ID 139) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction.
据我所知，当您得知某个事务已成为死锁受害者时，它已经被回滚。也许这就是我们出现异常的原因？
修复似乎是识别我们何时陷入僵局而不回滚，或者不使用事务，并在我们遇到主键冲突时重试。
使用 Entity Framework 6.0.0，我在关闭交易时看到异常。
我们一直在对 table 进行并发更改时遇到问题，所以我将其包装在一个事务中，现在我在回滚时遇到异常。
代码：
public LockInfo getSharedLock(string jobid)
{
using (var myDbContext = new MyDbContext())
{
using (var transaction = myDbContext.Database.BeginTransaction())
{
try
{
this.logger.log("Attempting to get shared lock for {0}", jobid);
var mylocks =
myDbContext.joblocks.Where(j => j.customerid == this.userContext.customerid)
.Where(j => j.jobid == jobid)
.Where(j => j.operatorid == this.userContext.operatorid);
var exclusiveLock = mylocks.FirstOrDefault(
j => j.lockstatus == LockInfo.LockState.Exclusive);
if (exclusiveLock != null)
{
this.logger.log("{0} already had exclusive lock, ignoring", jobid);
return LockInfo.populate(exclusiveLock);
}
var sharedLock = mylocks.FirstOrDefault(
j => j.lockstatus == LockInfo.LockState.Shared);
if (sharedLock != null)
{
this.logger.log("{0} already had shared lock, ignoring", jobid));
sharedLock.lockdt = DateTime.Now;
myDbContext.SaveChanges();
return LockInfo.populate(sharedLock);
}
var joblock = new joblock
{
customerid = this.userContext.customerid,
operatorid = this.userContext.operatorid,
jobid = jobid,
lockstatus = LockInfo.LockState.Shared,
sharedLock.lockdt = DateTime.Now
};
myDbContext.joblocks.Add(joblock);
myDbContext.SaveChanges();
transaction.Commit();
this.logger.log("Obtained shared lock for {0}", jobid);
return LockInfo.populate(joblock);
}
catch (Exception ex)
{
transaction.Rollback();
this.logger.logException(ex, "Exception in getSharedLock(\"{0}\")", jobid);
throw;
}
}
}
}
您可以在上面的代码中看到日志记录。我们也在数据库中启用了日志记录。日志跟踪：
===================
NORMAL TicketLockController.getLock("AK2015818002WL")
===================
SQL Opened connection at 9/22/2015 2:47:49 PM -05:00
===================
SQL Started transaction at 9/22/2015 2:47:49 PM -05:00
===================
NORMAL Attempting to get shared lock for AK2015818002WL
===================
SQL SELECT TOP (1) [Extent1].[customerid] AS [customerid]
,[Extent1].[jobid] AS [jobid]
,[Extent1].[lockdtdate] AS [lockdtdate]
,[Extent1].[lockdttime] AS [lockdttime]
,[Extent1].[operatorid] AS [operatorid]
,[Extent1].[lockstatus] AS [lockstatus]
,[Extent1].[changes] AS [changes]
FROM [dbo].[joblock] AS [Extent1]
WHERE ([Extent1].[customerid] = 'TESTTK')
AND ([Extent1].[jobid] = 'AK2015818002WL')
AND ([Extent1].[operatorid] = 'ADMIN')
AND (N'Exclusive' = [Extent1].[lockstatus])
===================
SQL SELECT TOP (1) [Extent1].[customerid] AS [customerid]
,[Extent1].[jobid] AS [jobid]
,[Extent1].[lockdtdate] AS [lockdtdate]
,[Extent1].[lockdttime] AS [lockdttime]
,[Extent1].[operatorid] AS [operatorid]
,[Extent1].[lockstatus] AS [lockstatus]
,[Extent1].[changes] AS [changes]
FROM [dbo].[joblock] AS [Extent1]
WHERE ([Extent1].[customerid] = 'TESTTK')
AND ([Extent1].[jobid] = 'AK2015818002WL')
AND ([Extent1].[operatorid] = 'ADMIN')
AND (N'Shared' = [Extent1].[lockstatus])
===================
SQL INSERT [dbo].[joblock] (
[customerid]
,[jobid]
,[lockdtdate]
,[lockdttime]
,[operatorid]
,[lockstatus]
,[changes]
)
VALUES (
@0
,@1
,@2
,@3
,@4
,@5
,NULL
)
===================
SQL Closed connection at 9/22/2015 2:47:50 PM -05:00
===================
EXCEPTION Unhandled exception caught: The underlying provider failed on Rollback.
===================
EXCEPTION Inner Exception: Value cannot be null.
Parameter name: connection
两次选择都成功了，然后由于某种原因插入失败了。抛出异常，由于某种原因，连接在 Rollback() 执行之前关闭。
知道我做错了什么吗？
==== 添加堆栈跟踪 ====
外部异常的堆栈跟踪：
at System.Data.Entity.Core.EntityClient.EntityTransaction.Rollback()
at korterra.kt_api.Shared.TicketLockWrangler.getSharedLock(String jobid)
at korterra.kt_ws.ApiControllers.Shared.TicketLockController.getSharedLock(TicketLockDTO ticketLockDTO)
at lambda_method(Closure , Object , Object[] )
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Tracing.ITraceWriterExtensions.<TraceBeginEndAsyncCore>d__18`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Tracing.ITraceWriterExtensions.<TraceBeginEndAsyncCore>d__18`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Filters.AuthorizationFilterAttribute.<ExecuteAuthorizationFilterAsyncCore>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()
内部异常的堆栈跟踪：
at System.Data.Entity.Utilities.Check.NotNull[T](T value, String parameterName)
at System.Data.Entity.Infrastructure.Interception.DbTransactionInterceptionContext.WithConnection(DbConnection connection)
at System.Data.Entity.Infrastructure.Interception.DbTransactionDispatcher.Rollback(DbTransaction transaction, DbInterceptionContext interceptionContext)
at System.Data.Entity.Core.EntityClient.EntityTransaction.Rollback()
经过讨论，我开始在尝试回滚之前记录异常 - 这揭示了错误。
交易陷入僵局：
Exception in getSharedLock("ticketnumber123456"): An error occurred while updating the entries. See the inner exception for details.
Inner Exception: An error occurred while updating the entries. See the inner exception for details.
Inner Exception: Transaction (Process ID 139) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction.
据我所知，当您得知某个事务已成为死锁受害者时，它已经被回滚。也许这就是我们出现异常的原因？
修复似乎是识别我们何时陷入僵局而不回滚，或者不使用事务，并在我们遇到主键冲突时重试。