ADO.Net Entity Framework Thread abort exception while reading the data - entity-framework

Question

I am facing a strange issue while reading a data using ADO.Net Entity framework.
I have two tables, "Surveys" and "PatientVists". "VisitId" is the primary key in "PatientVists" which is foreign key in "surveys" table.
I am using following query:
foreach (var survey in db.Surveys.Include(p => p.PatientVisit).Where(p => p.FacilityId == f.Id && p.IsCompleted == true && p.IsImaged == false).OrderBy(p => p.PatientVisit.MrnId).ThenBy(p => p.DateUpdated).ToList())
{
// reminign code
}
The above query seems pretty normal. But while executing the query I am getting thread abort exception. I can understand if I get timeout exception because of the large amount of the data. But I am not sure why I am getting thread abort exception. I am not explicitly spawning a thread. this code snippet is in the web service but I believe it's not related to that.
Following is the stack trace:
System.Threading.ThreadAbortException: Thread was being aborted.
at SNIReadSyncOverAsync(SNI_ConnWrapper* , SNI_Packet** , Int32 )
at SNINativeMethodWrapper.SNIReadSyncOverAsync(SafeHandle pConn, IntPtr& packet, Int32 timeout)
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.SqlDataReader.TryConsumeMetaData()
at System.Data.SqlClient.SqlDataReader.get_MetaData()
at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)
at System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
at System.Data.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues)
at System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
at System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
Is it reelected "ToList" operator or does "include" operator spawns a thread? Shall I replace it with Join? in general which is preferred method from performance perspective?
Please let me know if anyone has an insight into the particular exception
Thanks

Answer 1

I think this is the base thread that services the web application / service that is being timed out. If you spawn the process on its own thread, it should solve the problem.
You can also try the workaround posted here:
https://sharepoint.stackexchange.com/questions/9380/thread-was-being-aborted-with-sharepoint-2010
Add the code below to Web.Config:
< system.web >
< httpRuntime executionTimeout="36000" />
< / system.web >
It worked for me as a temporary solution until I change the code to run in its own thread!