Timeout error on running Scaffold-DbContext

Question

We use data-first approach, and use Scaffol-Dbcontext to reverse-engineer the data context.

Database is MySQL and we use Pomelo as provider.

It has been working fine for 283 database versions, but now the command crashes with the error:

The Command Timeout expired before the operation completed.

This is the command I use:

Scaffold-DbContext "server=localhost;userid=user;pwd=pass;port=3306;database=db_name;sslmode=none;" "Pomelo.EntityFrameworkCore.MySql" -d -o "OutputFolder" -v -f -context "ContextName"

And this is the full stack trace:

MySql.Data.MySqlClient.MySqlException (0x80004005): The Command Timeout expired before the operation completed. ---> MySql.Data.MySqlClient.MySqlException (0x80004005): The Command Timeout expired before the operation completed.
   at MySqlConnector.Protocol.Serialization.BufferedByteReader.ReadBytesAsync(IByteHandler byteHandler, ArraySegment`1 buffer, Int32 totalBytesToRead, IOBehavior ioBehavior) in C:\projects\mysqlconnector\src\MySqlConnector\Protocol\Serialization\BufferedByteReader.cs:line 36
   at MySqlConnector.Protocol.Serialization.ProtocolUtility.ReadPacketAsync(BufferedByteReader bufferedByteReader, IByteHandler byteHandler, Func`1 getNextSequenceNumber, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior) in C:\projects\mysqlconnector\src\MySqlConnector\Protocol\Serialization\ProtocolUtility.cs:line 406
   at MySqlConnector.Protocol.Serialization.ProtocolUtility.DoReadPayloadAsync(BufferedByteReader bufferedByteReader, IByteHandler byteHandler, Func`1 getNextSequenceNumber, ArraySegmentHolder`1 previousPayloads, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior) in C:\projects\mysqlconnector\src\MySqlConnector\Protocol\Serialization\ProtocolUtility.cs:line 459
   at MySqlConnector.Protocol.Serialization.StandardPayloadHandler.ReadPayloadAsync(ArraySegmentHolder`1 cache, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior) in C:\projects\mysqlconnector\src\MySqlConnector\Protocol\Serialization\StandardPayloadHandler.cs:line 37
   at MySqlConnector.Core.ServerSession.ReceiveReplyAsync(IOBehavior ioBehavior, CancellationToken cancellationToken) in C:\projects\mysqlconnector\src\MySqlConnector\Core\ServerSession.cs:line 645
--- End of stack trace from previous location where exception was thrown ---
   at MySqlConnector.Core.ServerSession.TryAsyncContinuation(Task`1 task) in C:\projects\mysqlconnector\src\MySqlConnector\Core\ServerSession.cs:line 1230
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
--- End of stack trace from previous location where exception was thrown ---
   at MySqlConnector.Core.ResultSet.ReadResultSetHeaderAsync(IOBehavior ioBehavior) in C:\projects\mysqlconnector\src\MySqlConnector\Core\ResultSet.cs:line 42
   at MySql.Data.MySqlClient.MySqlDataReader.ActivateResultSet(ResultSet resultSet) in C:\projects\mysqlconnector\src\MySqlConnector\MySql.Data.MySqlClient\MySqlDataReader.cs:line 74
   at MySql.Data.MySqlClient.MySqlDataReader.ReadFirstResultSetAsync(IOBehavior ioBehavior) in C:\projects\mysqlconnector\src\MySqlConnector\MySql.Data.MySqlClient\MySqlDataReader.cs:line 299
   at MySql.Data.MySqlClient.MySqlDataReader.CreateAsync(MySqlCommand command, CommandBehavior behavior, ResultSetProtocol resultSetProtocol, IOBehavior ioBehavior) in C:\projects\mysqlconnector\src\MySqlConnector\MySql.Data.MySqlClient\MySqlDataReader.cs:line 284
   at MySqlConnector.Core.TextCommandExecutor.ExecuteReaderAsync(String commandText, MySqlParameterCollection parameterCollection, CommandBehavior behavior, IOBehavior ioBehavior, CancellationToken cancellationToken) in C:\projects\mysqlconnector\src\MySqlConnector\Core\TextCommandExecutor.cs:line 37
   at MySql.Data.MySqlClient.MySqlCommand.ExecuteDbDataReader(CommandBehavior behavior) in C:\projects\mysqlconnector\src\MySqlConnector\MySql.Data.MySqlClient\MySqlCommand.cs:line 252
   at Pomelo.EntityFrameworkCore.MySql.Scaffolding.Internal.MySqlDatabaseModelFactory.GetConstraints()
   at Pomelo.EntityFrameworkCore.MySql.Scaffolding.Internal.MySqlDatabaseModelFactory.Create(DbConnection connection, IEnumerable`1 tables, IEnumerable`1 schemas)
   at Pomelo.EntityFrameworkCore.MySql.Scaffolding.Internal.MySqlDatabaseModelFactory.Create(String connectionString, IEnumerable`1 tables, IEnumerable`1 schemas)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineerScaffolder.ScaffoldModel(String connectionString, IEnumerable`1 tables, IEnumerable`1 schemas, String namespace, String language, String contextDir, String contextName, ModelReverseEngineerOptions modelOptions, ModelCodeGenerationOptions codeOptions)
   at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String outputContextDir, String dbContextClassName, IEnumerable`1 schemas, IEnumerable`1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String outputDbContextDir, String dbContextClassName, IEnumerable`1 schemaFilters, IEnumerable`1 tableFilters, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_1.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)

Related package versions:

Microsoft.AspNetCore.All 2.1.4
Pomelo.EntityFrameworkCore.MySql 2.1.2

It's important to note that this only happens on my computer (VS Professional 2017 v15.8.5). The other coworkers can run the same command, with a backup of my database, without any error.

Can you point me in the right direction? So far I have tested (without success):

Update all packages.
Update Visual Studio
Delete nuget folder and restore packages
Tried with several databases (some work, some don't, but not sure what's the difference between them)
Added the "Connect timeout=300" property to the connection string (same error, but it takes 5 minutes)

Sounds like network issues. Did you try with your firewall desactivated ? Your database in on the same computer right (i see a localhost) ? — Benjamin K
Thanks for your suggestion. Just tried now disabling nod32 firewall, and problem persists. Yes, database server is on the same computer than visual studio. — Dídac Punyet
You might want to SHOW GLOBAL VARIABLES LIKE '%time%'; and see if anything rings a bell for you. — Wilson Hauck
@WilsonHauck Nothing weird on it. Tried to put a bigger connect_timeout value, but same result. — Dídac Punyet

Daniel Botero Correa Daniel Botero Correa · Accepted Answer · 2019-08-20T18:07:09

Next time, try to add

Connection Timeout=300 (Time in seconds)
default command timeout=300 (Time in seconds)

try the following connection string:

dotnet ef dbcontext scaffold "server=simycotest.ddns.net;userid=xxxxx;password=xxxxx;database=xxxxx;Connection Timeout=300;default command timeout=300" "Pomelo.EntityFrameworkCore.MySql" -o .\DbModels -f

For more info about connection string in MySql

Timeout error on running Scaffold-DbContext

2 Answers