基础提供程序在Open上失败？

Question

I created an application using the Entity framework 6 with SQL. It was working fine. suddenly yesterday I got an error twice from the entity framework as shown below, After that this issue not raised yet now.

System.Data.Entity.Core.EntityException: The underlying provider failed on Open. ---> System.Transactions.TransactionManagerCommunicationException: Network access for Distributed Transaction Manager (MSDTC) has been disabled. Please enable DTC for network access in the security configuration for MSDTC using the Component Services Administrative tool. ---> System.Runtime.InteropServices.COMException: The transaction manager has disabled its support for remote/network transactions. (Exception from HRESULT: 0x8004D024)
   at System.Transactions.Oletx.IDtcProxyShimFactory.ReceiveTransaction(UInt32 propgationTokenSize, Byte[] propgationToken, IntPtr managedIdentifier, Guid& transactionIdentifier, OletxTransactionIsolationLevel& isolationLevel, ITransactionShim& transactionShim)
   at System.Transactions.TransactionInterop.GetOletxTransactionFromTransmitterPropigationToken(Byte[] propagationToken)
   --- End of inner exception stack trace ---
   at System.Transactions.Oletx.OletxTransactionManager.ProxyException(COMException comException)
   at System.Transactions.TransactionInterop.GetOletxTransactionFromTransmitterPropigationToken(Byte[] propagationToken)
   at System.Transactions.TransactionStatePSPEOperation.PSPEPromote(InternalTransaction tx)
   at System.Transactions.TransactionStateDelegatedBase.EnterState(InternalTransaction tx)
   at System.Transactions.EnlistableStates.Promote(InternalTransaction tx)
   at System.Transactions.Transaction.Promote()
   at System.Transactions.TransactionInterop.ConvertToOletxTransaction(Transaction transaction)
   at System.Transactions.TransactionInterop.GetExportCookie(Transaction transaction, Byte[] whereabouts)
   at System.Data.SqlClient.SqlInternalConnection.EnlistNonNull(Transaction tx)
   at System.Data.ProviderBase.DbConnectionPool.PrepareConnection(DbConnection owningObject, DbConnectionInternal obj, Transaction transaction)
   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.Open()
   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<>c__DisplayClass1.<Execute>b__0()
   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
   at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
   --- End of inner exception stack trace ---
   at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
   at System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection()
   at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClassb.<GetResults>b__9()
   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
   at System.Lazy`1.CreateValue()
   at System.Lazy`1.LazyInitValue()
   at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector)

The logic behind the code as follows,

1. Transaction started

2. If any data is there to insert, Insertion will happen

3. Context will be disposed and recreated here.

4. 10,000 records will be fetched

5. Close transaction or roll back.

Both time error occurs in step 4. These are my concern

1. What is this issue and why this issue is not constant?
2. How to skip this issue in future?

Answer 1

Three options: You need to enable MSDTC on your server. Or when you dispose of the context you also have to call .Complete() on the transaction and dispose of the transaction as well, creating the context outside of the original TransactionScope. Or you should be able to fetch the data on the original context instead of disposing of it first. What happens is that when you recreate the context inside of the TransactionScope, it treats it as a 2nd connection and essentially promotes that to need an MSDTC call.