Develop Reference

Signalr SQL backplane causes The wait operation timed out exception

We have recently implemented the backplane using sql server. The server that we created the backplane contains other databases as well. These other databases are accessed by different applications which are on different servers. For stress testing we implemented a simple signalr client program which sends a message to the server every 30 seconds. There are two servers which are handled by a load balancer. The backplane works perfectly when number of clients are small.
The issue is when the number of clients are higher. (closer to 50 or more). The following exception is thrown by other applications that tries to use the database server for a different database.
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
--- End of inner exception stack trace ---
at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
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.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)
--- End of inner exception stack trace ---
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.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.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source)
at System.Linq.Queryable.Count[TSource](IQueryable`1 source)
Because of this exception all the other applications breaks since they can not access the database. The problem immidiately fixes if we disable the backplane. (stopping the two signalr servers). Is this the expected behavior when using the backplane with high number of users or is it an issue with the backplane?
PS - We noticed that the machines that throw these exceptions have more than 3000 threads allocated for w3wp.exe process. Seems like they are stuck on a operation.

If you are not using asynchronous calls then its feasible that one of the message threads are taking longer than expected, and while it is waiting to return another thread is stuck and you are basically getting threadlocked.
The 2 possible solutions I can think of is:
1) Make sure you are making async calls to the database.
2) Make sure you have enough threads setup on the IIS server. You need a minimum of 12, default setup is usually only 1.

Command timeout SQL Server 2014 + Entity Framework

I have installed SQL Server 2014 on my new PC yesterday, it was working until I restarted my PC, now I am getting this error.
I have started / restarted SQL Server services etc..
I can still connect from Management Studio.
When adding EF model to my asp.net project, it can list databases and get tables to generate EF model, but I can't do anything with the database because of this timeout exception, database is almost empty (only 1 table with 1 user in) and I am executing simple queries (like select, add)
using(var db = new TestEntities())
{
var _user = db.Users.FirstOrDefault(); // timeout exception
}
Unhandled Exception: System.Data.Entity.Core.EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details. ---> 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
--- End of inner exception stack trace ---
at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction)
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.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, Boolean describeParameterEncryptionRequest)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource1 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.Common.DbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<Reader>b__c(DbCommand t, DbCommandInterceptionContext1 c)
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func3 operation, TInterceptionContext interceptionContext, Action3 executing, Action3 executed)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)
at System.Data.Entity.Internal.InterceptableDbCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
--- End of inner exception stack trace ---
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.ObjectQuery1.<>c__DisplayClass7.<GetResults>b__6()
at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
at System.Data.Entity.Core.Objects.ObjectQuery1.<>c__DisplayClass7.<GetResults>b__5()
at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func1 operation)
at System.Data.Entity.Core.Objects.ObjectQuery1.GetResults(Nullable1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
at System.Data.Entity.Internal.LazyEnumerator1.MoveNext()
at System.Linq.Enumerable.Single[TSource](IEnumerable1 source)
at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__3[TResult](IEnumerable1 sequence)
at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.ExecuteSingle[TResult](IEnumerable1 query, Expression queryRoot)
at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[TResult](Expression expression)
at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression)
at System.Linq.Queryable.Count[TSource](IQueryable1 source)

Set the timeout on the command
SqlCommand.CommandTimeout
There is probably another problem
And test a simple select like select ##versino

Press window + r > "services.msc" > SQL Server (MSSQLSERVER) > Right Click > Start
The sql server instance is closed therefore server couldn't respond.

Could it be that the TCP/IP protocol is not enabled? Check SQL Server Configuration Manager.
It could also be that it's not accepting remote connections. For that, you need to check with SQL Server Management Studio, server properties, Connections.

Linq IEnumerable Error which occurs spontaneously [duplicate]

This question already has answers here:
Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. The statement has been terminated
(25 answers)
Closed 7 years ago.
I have this problem where I perform a Linq query then convert it to a List object. Let me add that this error only occurs sometimes and it happens in production. When the IEnumerable object is converted to a List an error is thrown. I have a logger set up and this is the exception type, stack trace, and inner exception. Any thoughts on how i can refactor this snippet of code to make it more stable would be much appreciated. Here is the code which throws the error
var isMember = db.DN2_Member.Where(m =>
m.Partner_Contract_Nbr.ToLower() == member.DentalMemberId.ToLower()
&& m.Mbr_First_Nm.ToLower() == member.DentalMemberFirstName.ToLower()
//&& m.Mbr_Mid_Nm.ToLower().Trim() == memberMiddleName.ToLower()
&& m.Mbr_Last_Nm.ToLower() == member.DentalMemberLastName.ToLower()
&& m.DW_Rec_End_Dt == null
&& m.Mbr_Suc_Title.ToLower() == membersuffix.ToLower().Replace(".", ""));
//Forces the query to evaluate to a definitive collection; necessary for querying it further
var memberList = isMember.ToList();
Line 88 is var memberList = isMember.ToList();
Here is the Exception Details.
Exception Type: An error occurred while executing the command
definition. See the inner exception for details.
Stack Trace: 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__DisplayClass3.b__1()
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.b__0()
at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() at
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) at
System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) at
DentalTHSEnrollmentService.WebHost.THSService.GetMember(DentalMember
member) in
e:\GoAgent\pipelines\DentalTHSEnrollmentService_Master\product\app\DentalTHSEnrollmentService.WebHost\THSService.svc.cs:line
88
Inner Exception:
System.Data.Entity.Core.EntityCommandExecutionException: An error
occurred while executing the command definition. See the inner
exception for details. ---> 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 ---
End of inner exception stack trace --- at
System.Data.SqlClient.SqlConnection.OnError(SqlException exception,
Boolean breakConnection, Action`1 wrapCloseInAction) at
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject
stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) 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.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) --- End of inner exception
stack trace --- 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__DisplayClass3.b__1()
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.b__0()
at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() at
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) at
System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) at
DentalTHSEnrollmentService.WebHost.THSService.GetMember(DentalMember
member) in
e:\GoAgent\pipelines\DentalTHSEnrollmentService_Master\product\app\DentalTHSEnrollmentService.WebHost\THSService.svc.cs:line
88

The crux of your error message is:
System.Data.SqlClient.SqlException: Timeout expired. The timeout
period elapsed prior to completion of the operation or the server is
not responding.
Essentially your sql query is taking longer to run than your command timeout. You should add indexing to your table / tables to help with the performance.

Update-Database MVC automatic migrations - There is already an object named 'StationsArrangeds' in the database

Update-Database command was giving this error:
There is already an object named 'StationsArrangeds' in the database.
So I deleted this table and now I'm getting this exception while trying to update database.
Using StartUp project 'MetroTrain'. Using NuGet project 'MetroTrain'.
Specify the '-Verbose' flag to view the SQL statements being applied
to the target database.
System.Data.Entity.Core.EntityCommandExecutionException: An error
occurred while executing the command definition. See the inner
exception for details.
System.Data.SqlClient.SqlException:
Invalid object name 'dbo.StationsArranged'.
at System.Data.SqlClient.SqlConnection.OnError(SqlException exception,
Boolean breakConnection, Action1 wrapCloseInAction)
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.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, Boolean describeParameterEncryptionRequest)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior
cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String
method, TaskCompletionSource1 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.Common.DbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<>c__DisplayClassb.<Reader>b__8()
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher1.Dispatch[TInterceptionContext,TResult](Func1 operation, TInterceptionContext interceptionContext, Action1 executing, Action1 executed)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)
at System.Data.Entity.Internal.InterceptableDbCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
--- End of inner exception
Stack trace ---
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.ObjectQuery1.<>c__DisplayClassb.b__a()
at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
at System.Data.Entity.Core.Objects.ObjectQuery1.<>c__DisplayClassb.b__9()
at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func1 operation)
at System.Data.Entity.Core.Objects.ObjectQuery1.GetResults(Nullable1
forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery1.System.Collections.Generic.IEnumerable.GetEnumerator>b__0()
at System.Lazy1.CreateValue()
at System.Lazy1.LazyInitValue()
at System.Lazy1.get_Value()
at System.Data.Entity.Internal.LazyEnumerator1.MoveNext()
at System.Collections.Generic.List1..ctor(IEnumerable1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at MetroTrain.Models.StationsContext..ctor() in c:\Users\ghousia
pc\Dropbox\iMaq\MetroTrain\MetroTrain\Models\StationsContext.cs:line
22
--- End of stack trace from previous location where exception was thrown >
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Data.Entity.Infrastructure.DbContextInfo.CreateInstance()
at System.Data.Entity.Infrastructure.DbContextInfo..ctor(Type
contextType, DbProviderInfo modelProviderInfo, AppConfig config,
DbConnectionInfo connectionInfo)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration
configuration, DbContext usersContext)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration
configuration)
at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.GetMigrator()
at System.Data.Entity.Migrations.Design.ToolingFacade.UpdateRunner.Run()
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner
runner)
at System.Data.Entity.Migrations.Design.ToolingFacade.Update(String
targetMigration, Boolean force)
at System.Data.Entity.Migrations.UpdateDatabaseCommand.<>c__DisplayClass2.<.ctor>b__0()
at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action
command)
An error occurred while executing the command definition. See the inner exception for details.
I've gone through forums no solution found.

Manually deleting tables in code first causes EF to lose track of your model changes.
You can reset code first migrations by deleting migration history table and re-enable migration.

This is mostly because your database Migration table ("__MigrationHistory") is not sync with your Migration
you can change your Database Name in default connection string and create new database.
after create new database compare it with existing Database menualy and sync "__MigrationHistory" from new database to existing for later Migrate

Some part of your SQL statement is nested too deeply. Rewrite the query or break it up into smaller queries

I have action in my controller which calls the following method :
public IQueryable<AaaUserContactInfo> getcontactinfo(long[] id)
{
var organizationsiteids = from accountsitemapping in entities.AccountSiteMappings
where id.Any(accountid => accountsitemapping.ACCOUNTID == accountid)
select accountsitemapping.SITEID;
var usersdepts = from userdept in entities.UserDepartments
join deptdefinition in entities.DepartmentDefinitions on userdept.DEPTID equals deptdefinition.DEPTID
where organizationsiteids.Any(accountid => deptdefinition.SITEID == accountid)
select userdept;
var contactsinfos = from userdept in usersdepts
join contactinfo in entities.AaaUserContactInfoes on userdept.USERID equals contactinfo.USER_ID
select contactinfo;
return contactsinfos;
}
But when I run the application and I navigate to the action method the folowing error will be raised on the view level:-
System.Data.EntityCommandExecutionException was unhandled by user code
HResult=-2146232004
Message=An error occurred while executing the command definition. See the inner exception for details.
Source=System.Data.Entity
StackTrace:
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.Data.Entity.Internal.Linq.InternalQuery`1.GetEnumerator()
at System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable<TResult>.GetEnumerator()
at System.Linq.Enumerable.Count[TSource](IEnumerable`1 source)
at ASP._Page_Views_Home_CustomersDetails_cshtml.Execute() in c:\Users\Administrator\Desktop\new app DEMO2\MvcApplication4 - LATEST -\MvcApplication4\Views\Home\CustomersDetails.cshtml:line 6
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.StartPage.RunPage()
at System.Web.WebPages.StartPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance)
at System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer)
at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
InnerException: System.Data.SqlClient.SqlException
HResult=-2146232060
Message=Some part of your SQL statement is nested too deeply. Rewrite the query or break it up into smaller queries.
Source=.Net SqlClient Data Provider
ErrorCode=-2146232060
Class=15
LineNumber=105
Number=191
Procedure=""
StackTrace:
at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
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)
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.Common.DbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
InnerException:
So what is causing this error??
UPDATED:-

LINQ, for most of its commands, employs deferred execution. It waits until you actually call for the data before it sends the query to that database. Here it looks like all of those queries are being deferred until later, when you try to grab something out of contactInfos.
I would try having it execute, like by throwing a .ToList() somewhere, to try and reduce the nesting that would be otherwise going on in the SQL.
EDIT: Since, per the comments, you appear to be getting the error on the first query, could you please try and having it say where id.Contains(accountsitemapping.ACCOUNTID)?

For future reference, you can log the generated SQL using:
var db = new DbContext();
db.Database.Log = Console.Write;
This will allow you to figure out which part is getting deeply nested. From there, you may have to re-write your query to load expensive calculations in a second step. Or consider writing it as a stored procedure.