Oracle.ManagedDataAccess.Client throws NullReferenceException
I'm using Entity Framework 6 with Oracle.ManagedDataAccess. Sporadically I get this error:
System.NullReferenceException: Object reference not set to an instance of an object.
at Oracle.ManagedDataAccess.Client.OracleConnection.get_m_majorVersion()
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues)
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__DisplayClass7.<GetResults>b__5()
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.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
at MyApp.MyScheduler.AddSampleOperation(SampleOperation sampleOperation)
It happens specifically when I make a call like:
_dbContext.SampleOperations.AsNoTracking().First(so => so.SampleOperationId == sampleOperation.SampleOperationId);
To be clear, this is not a NullReferenceException happening with code that I control. It's happening in the Oracle client code, and it only happens sporadically. I can reproduce the same steps multiple times and the error won't happen, then eventually it does. I tried removing Oracle.ManagedDataAccess.Client from the GAC, but that didn't help.
I'm hoping someone else has seen this error. I'm using the following versions from NuGet:
Oracle.ManagedDataAccess: 12.1.24160719
Oracle.ManagedDataAccess.EntityFramework: 12.1.2400
EntityFramework: 6.1.3
Could it be something that was fixed in a later version Oracle.ManagedDataAccess?
c# oracle entity-framework
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
|
show 6 more comments
I'm using Entity Framework 6 with Oracle.ManagedDataAccess. Sporadically I get this error:
System.NullReferenceException: Object reference not set to an instance of an object.
at Oracle.ManagedDataAccess.Client.OracleConnection.get_m_majorVersion()
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues)
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__DisplayClass7.<GetResults>b__5()
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.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
at MyApp.MyScheduler.AddSampleOperation(SampleOperation sampleOperation)
It happens specifically when I make a call like:
_dbContext.SampleOperations.AsNoTracking().First(so => so.SampleOperationId == sampleOperation.SampleOperationId);
To be clear, this is not a NullReferenceException happening with code that I control. It's happening in the Oracle client code, and it only happens sporadically. I can reproduce the same steps multiple times and the error won't happen, then eventually it does. I tried removing Oracle.ManagedDataAccess.Client from the GAC, but that didn't help.
I'm hoping someone else has seen this error. I'm using the following versions from NuGet:
Oracle.ManagedDataAccess: 12.1.24160719
Oracle.ManagedDataAccess.EntityFramework: 12.1.2400
EntityFramework: 6.1.3
Could it be something that was fixed in a later version Oracle.ManagedDataAccess?
c# oracle entity-framework
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
1
Version 12.1 was the first release of Oracle.ManagedDataAccess. I would give a try on newer version, i.e. 12.2
– Wernfried Domscheit
Nov 15 '18 at 17:18
1
You can now get the Oracle drivers from NuGet nuget.org/packages/Oracle.ManagedDataAccess , so try that. And also make sure that you're not accessing a DbContext instance from multiple threads, which can cause sporadic failures with any provider.
– David Browne - Microsoft
Nov 15 '18 at 17:20
I'm going to try upgrading to 12.2. @DavidBrowne-Microsoft question - if all access to the DbContext is always wrapped in a lock, would that prevent the sporadic failures?
– Jeff F.
Nov 15 '18 at 19:47
Yes. The DbContext can be accessed from different threads, just not at the same time. Although for performance you normally would not do that.
– David Browne - Microsoft
Nov 15 '18 at 20:12
1
I found a place where the db context was being accessed potentially from a separate thread without a lock. That might actually be the underlying cause of this. You might want to search your code for that.
– Jeff F.
Nov 30 '18 at 19:57
|
show 6 more comments
I'm using Entity Framework 6 with Oracle.ManagedDataAccess. Sporadically I get this error:
System.NullReferenceException: Object reference not set to an instance of an object.
at Oracle.ManagedDataAccess.Client.OracleConnection.get_m_majorVersion()
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues)
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__DisplayClass7.<GetResults>b__5()
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.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
at MyApp.MyScheduler.AddSampleOperation(SampleOperation sampleOperation)
It happens specifically when I make a call like:
_dbContext.SampleOperations.AsNoTracking().First(so => so.SampleOperationId == sampleOperation.SampleOperationId);
To be clear, this is not a NullReferenceException happening with code that I control. It's happening in the Oracle client code, and it only happens sporadically. I can reproduce the same steps multiple times and the error won't happen, then eventually it does. I tried removing Oracle.ManagedDataAccess.Client from the GAC, but that didn't help.
I'm hoping someone else has seen this error. I'm using the following versions from NuGet:
Oracle.ManagedDataAccess: 12.1.24160719
Oracle.ManagedDataAccess.EntityFramework: 12.1.2400
EntityFramework: 6.1.3
Could it be something that was fixed in a later version Oracle.ManagedDataAccess?
c# oracle entity-framework
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
I'm using Entity Framework 6 with Oracle.ManagedDataAccess. Sporadically I get this error:
System.NullReferenceException: Object reference not set to an instance of an object.
at Oracle.ManagedDataAccess.Client.OracleConnection.get_m_majorVersion()
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)
at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues)
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__DisplayClass7.<GetResults>b__5()
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.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
at MyApp.MyScheduler.AddSampleOperation(SampleOperation sampleOperation)
It happens specifically when I make a call like:
_dbContext.SampleOperations.AsNoTracking().First(so => so.SampleOperationId == sampleOperation.SampleOperationId);
To be clear, this is not a NullReferenceException happening with code that I control. It's happening in the Oracle client code, and it only happens sporadically. I can reproduce the same steps multiple times and the error won't happen, then eventually it does. I tried removing Oracle.ManagedDataAccess.Client from the GAC, but that didn't help.
I'm hoping someone else has seen this error. I'm using the following versions from NuGet:
Oracle.ManagedDataAccess: 12.1.24160719
Oracle.ManagedDataAccess.EntityFramework: 12.1.2400
EntityFramework: 6.1.3
Could it be something that was fixed in a later version Oracle.ManagedDataAccess?
c# oracle entity-framework
c# oracle entity-framework
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
asked Nov 15 '18 at 16:29
Jeff F.Jeff F.
81449
81449
1
Version 12.1 was the first release of Oracle.ManagedDataAccess. I would give a try on newer version, i.e. 12.2
– Wernfried Domscheit
Nov 15 '18 at 17:18
1
You can now get the Oracle drivers from NuGet nuget.org/packages/Oracle.ManagedDataAccess , so try that. And also make sure that you're not accessing a DbContext instance from multiple threads, which can cause sporadic failures with any provider.
– David Browne - Microsoft
Nov 15 '18 at 17:20
I'm going to try upgrading to 12.2. @DavidBrowne-Microsoft question - if all access to the DbContext is always wrapped in a lock, would that prevent the sporadic failures?
– Jeff F.
Nov 15 '18 at 19:47
Yes. The DbContext can be accessed from different threads, just not at the same time. Although for performance you normally would not do that.
– David Browne - Microsoft
Nov 15 '18 at 20:12
1
I found a place where the db context was being accessed potentially from a separate thread without a lock. That might actually be the underlying cause of this. You might want to search your code for that.
– Jeff F.
Nov 30 '18 at 19:57
|
show 6 more comments
1
Version 12.1 was the first release of Oracle.ManagedDataAccess. I would give a try on newer version, i.e. 12.2
– Wernfried Domscheit
Nov 15 '18 at 17:18
1
You can now get the Oracle drivers from NuGet nuget.org/packages/Oracle.ManagedDataAccess , so try that. And also make sure that you're not accessing a DbContext instance from multiple threads, which can cause sporadic failures with any provider.
– David Browne - Microsoft
Nov 15 '18 at 17:20
I'm going to try upgrading to 12.2. @DavidBrowne-Microsoft question - if all access to the DbContext is always wrapped in a lock, would that prevent the sporadic failures?
– Jeff F.
Nov 15 '18 at 19:47
Yes. The DbContext can be accessed from different threads, just not at the same time. Although for performance you normally would not do that.
– David Browne - Microsoft
Nov 15 '18 at 20:12
1
I found a place where the db context was being accessed potentially from a separate thread without a lock. That might actually be the underlying cause of this. You might want to search your code for that.
– Jeff F.
Nov 30 '18 at 19:57
1
1
Version 12.1 was the first release of Oracle.ManagedDataAccess. I would give a try on newer version, i.e. 12.2
– Wernfried Domscheit
Nov 15 '18 at 17:18
Version 12.1 was the first release of Oracle.ManagedDataAccess. I would give a try on newer version, i.e. 12.2
– Wernfried Domscheit
Nov 15 '18 at 17:18
1
1
You can now get the Oracle drivers from NuGet nuget.org/packages/Oracle.ManagedDataAccess , so try that. And also make sure that you're not accessing a DbContext instance from multiple threads, which can cause sporadic failures with any provider.
– David Browne - Microsoft
Nov 15 '18 at 17:20
You can now get the Oracle drivers from NuGet nuget.org/packages/Oracle.ManagedDataAccess , so try that. And also make sure that you're not accessing a DbContext instance from multiple threads, which can cause sporadic failures with any provider.
– David Browne - Microsoft
Nov 15 '18 at 17:20
I'm going to try upgrading to 12.2. @DavidBrowne-Microsoft question - if all access to the DbContext is always wrapped in a lock, would that prevent the sporadic failures?
– Jeff F.
Nov 15 '18 at 19:47
I'm going to try upgrading to 12.2. @DavidBrowne-Microsoft question - if all access to the DbContext is always wrapped in a lock, would that prevent the sporadic failures?
– Jeff F.
Nov 15 '18 at 19:47
Yes. The DbContext can be accessed from different threads, just not at the same time. Although for performance you normally would not do that.
– David Browne - Microsoft
Nov 15 '18 at 20:12
Yes. The DbContext can be accessed from different threads, just not at the same time. Although for performance you normally would not do that.
– David Browne - Microsoft
Nov 15 '18 at 20:12
1
1
I found a place where the db context was being accessed potentially from a separate thread without a lock. That might actually be the underlying cause of this. You might want to search your code for that.
– Jeff F.
Nov 30 '18 at 19:57
I found a place where the db context was being accessed potentially from a separate thread without a lock. That might actually be the underlying cause of this. You might want to search your code for that.
– Jeff F.
Nov 30 '18 at 19:57
|
show 6 more comments
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1
Version 12.1 was the first release of Oracle.ManagedDataAccess. I would give a try on newer version, i.e. 12.2
– Wernfried Domscheit
Nov 15 '18 at 17:18
1
You can now get the Oracle drivers from NuGet nuget.org/packages/Oracle.ManagedDataAccess , so try that. And also make sure that you're not accessing a DbContext instance from multiple threads, which can cause sporadic failures with any provider.
– David Browne - Microsoft
Nov 15 '18 at 17:20
I'm going to try upgrading to 12.2. @DavidBrowne-Microsoft question - if all access to the DbContext is always wrapped in a lock, would that prevent the sporadic failures?
– Jeff F.
Nov 15 '18 at 19:47
Yes. The DbContext can be accessed from different threads, just not at the same time. Although for performance you normally would not do that.
– David Browne - Microsoft
Nov 15 '18 at 20:12
1
I found a place where the db context was being accessed potentially from a separate thread without a lock. That might actually be the underlying cause of this. You might want to search your code for that.
– Jeff F.
Nov 30 '18 at 19:57