Devart Forums

I am running MySQL 5.5 and ever since I upgraded to the latest version of MySQL dotconnect, it seems like MySQL is locking up and not accepting new connections.

Restarting MySQL solves the issue but it has happened at least once a day for the last several days.

But I don't know what is happening, there is nothing in the MySQL error logs.

Anything off the top of your head that would cause MySQL to stop accepting new connections or requests?

Found this in the IIS logs, this was inputted just before it stopped working:



<E2ETraceEvent xmlns="http://schemas.microsoft.com/2004/06/E2ETraceEvent">
<System xmlns="http://schemas.microsoft.com/2004/06/wi ... log/system">
<EventID>131077</EventID>
<Type>3</Type>
<SubType Name="Critical">0</SubType>
<Level>1</Level>
<TimeCreated SystemTime="2013-12-24T23:41:05.8108436Z" />
<Source Name="System.ServiceModel" />
<Correlation ActivityID="{04a8fe88-eb1c-44c9-860f-71098d99bb9b}" />
<Execution ProcessName="w3wp" ProcessID="5140" ThreadID="14" />
<Channel />
<Computer>IISWATSO</Computer>
</System>
<ApplicationData>
<TraceData>
<DataItem>
<TraceRecord Severity="Critical" Channel="Operational" xmlns="http://schemas.microsoft.com/2004/10/E2 ... raceRecord">
<TraceIdentifier>http://msdn.microsoft.com/en-US/library ... Identifier>
<Description>Unhandled exception. Exception details: System.InvalidOperationException: The LinkedList is empty.
at System.Collections.Generic.LinkedList`1.RemoveFirst()
at Devart.Common.m.a()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()</Description>
<AppDomain>/LM/W3SVC/2/ROOT/ReservationService-2-130324014985792436</AppDomain>
<Exception>
<ExceptionType>System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType>
<Message>The LinkedList is empty.</Message>
<StackTrace>
at System.Collections.Generic.LinkedList`1.RemoveFirst()
at Devart.Common.m.a()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
</StackTrace>
<ExceptionString>System.InvalidOperationException: The LinkedList is empty.
at System.Collections.Generic.LinkedList`1.RemoveFirst()
at Devart.Common.m.a()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()</ExceptionString>
</Exception>
</TraceRecord>
</DataItem>
</TraceData>
</ApplicationData>
</E2ETraceEvent>



Subsequent calls get the following error until we restart MySQL:

<E2ETraceEvent xmlns="http://schemas.microsoft.com/2004/06/E2ETraceEvent">
<System xmlns="http://schemas.microsoft.com/2004/06/wi ... log/system">
<EventID>131076</EventID>
<Type>3</Type>
<SubType Name="Error">0</SubType>
<Level>2</Level>
<TimeCreated SystemTime="2013-12-24T23:43:09.7684436Z" />
<Source Name="System.ServiceModel" />
<Correlation ActivityID="{429ad55c-e8a0-4c05-9cec-e6e2b77e5110}" />
<Execution ProcessName="w3wp" ProcessID="892" ThreadID="10" />
<Channel />
<Computer>IISWATSO</Computer>
</System>
<ApplicationData>
<TraceData>
<DataItem>
<TraceRecord Severity="Error" Channel="Operational" xmlns="http://schemas.microsoft.com/2004/10/E2 ... raceRecord">
<TraceIdentifier>http://msdn.microsoft.com/en-US/library ... Identifier>
<Description>Handling an exception. Exception details: System.ServiceModel.FaultException`1[System.ServiceModel.DomainServices.Hosting.DomainServiceFault]: An exception occurred. Please contact your administrator. Inner exception message: Lost connection to MySQL server during query (Fault Detail is equal to System.ServiceModel.DomainServices.Hosting.DomainServiceFault).</Description>
<AppDomain>/LM/W3SVC/2/ROOT/ReservationService-1-130324021846672436</AppDomain>
<Exception>
<ExceptionType>System.ServiceModel.FaultException`1[[System.ServiceModel.DomainServices.Hosting.DomainServiceFault, System.ServiceModel.DomainServices.Hosting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]], System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType>
<Message>An exception occurred. Please contact your administrator. Inner exception message: Lost connection to MySQL server during query</Message>
<StackTrace>
at System.ServiceModel.DomainServices.Hosting.QueryOperationBehavior`1.QueryOperationInvoker.InvokeCore(Object instance, Object[] inputs, Object[]& outputs)
at System.ServiceModel.DomainServices.Hosting.DomainOperationInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)
</StackTrace>
<ExceptionString>System.ServiceModel.FaultException`1[System.ServiceModel.DomainServices.Hosting.DomainServiceFault]: An exception occurred. Please contact your administrator. Inner exception message: Lost connection to MySQL server during query (Fault Detail is equal to System.ServiceModel.DomainServices.Hosting.DomainServiceFault).</ExceptionString>
</Exception>
</TraceRecord>
</DataItem>
</TraceData>
</ApplicationData>
</E2ETraceEvent>

Please give us the following information:
1. Your current version of dotConnect for MySQL is 8.2.55, the previous one is 6.50.214. Is this correct?
2. Specify the exact version (5.5.XX) of your MySQL server.
3. Are you using the MySqlMonitor object in your code? If yes, try disabling it and check if this helps.
4. If possible, try to localize the issue to provide us with more information about it (or send us a test project).

There was an instance of mysqlmonitor, I will disable that and let you know if the problem persists.

In the meanawhile here is the response to your questions:

1. yes
2. MySQL v. 5.5.13

I'll try and localize the issue if it continues to occur. Thank you.