Connection error occurred after upgrading from 5. x to 6. x

[cape1999]

Describe the bug

Exception message:Connection Timeout Expired.  The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement.  This could be because the pre-login handshake failed or the server was unable to respond back in time.  The duratio
n spent while attempting to connect to this server was - [Pre-Login] initialization=9055; handshake=23;
Stack trace:
at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction
)
   at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, SqlCommand command, Boolean callerHasConnectionLock, Boolean asyncClose)
   at Microsoft.Data.SqlClient.TdsParserStateObject.ThrowExceptionAndWarning(Boolean callerHasConnectionLock, Boolean asyncClose)
   at Microsoft.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error)
   at Microsoft.Data.SqlClient.TdsParserStateObject.ReadSniSyncOverAsync()
   at Microsoft.Data.SqlClient.TdsParserStateObject.TryReadNetworkPacket()
   at Microsoft.Data.SqlClient.TdsParser.ConsumePreLoginHandshake(SqlConnectionEncryptOption encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean& marsCapable, Boolean& fedAuthRequired, Boolean tlsFirst, String serverCertificateFil
ename)
   at Microsoft.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, TimeoutTimer timeout, SqlConnectionString connectionOptions, Boolean withFailover)
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, TimeoutTimer timeout, Boolean withFailover)
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, Time
outTimer timeout)
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)      
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redir
ectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, Boolean applyTransientFaultHandling, String accessToken, IDbConnectionPool pool, Func`3 accessTokenCallback)
   at Microsoft.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionPoolGroupProviderInfo poolGroupProviderInfo, IDbConnectionPool pool, DbConnection owningConnection, DbConnect
ionOptions userOptions)
   at Microsoft.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(IDbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   at Microsoft.Data.SqlClient.ConnectionPool.WaitHandleDbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at Microsoft.Data.SqlClient.ConnectionPool.WaitHandleDbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at Microsoft.Data.SqlClient.ConnectionPool.WaitHandleDbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConne
ctionInternal& connection)
   at Microsoft.Data.SqlClient.ConnectionPool.WaitHandleDbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 taskCompletionSource, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at Microsoft.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at Microsoft.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at Microsoft.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at Microsoft.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry, SqlConnectionOverrides overrides)
   at Microsoft.Data.SqlClient.SqlConnection.Open(SqlConnectionOverrides overrides)
   at Microsoft.Data.SqlClient.SqlConnection.Open()
   at CaiTools.Program.Main(String[] args) in D:\repos\CaiTools\CaiTools\Program.cs:line 82

To reproduce

        using var conn = new SqlConnection("Data Source=mydatabase ipv4Address;Initial Catalog=mydatabasename;Integrated Security=False;User ID=user ;Password=password;Connect Timeout=5;Command Timeout=5;TrustServerCertificate=True;Encrypt=False");
        var watch = Stopwatch.StartNew();
        try {
            conn.Open();
            Console.WriteLine($"Success，Time: {watch.ElapsedMilliseconds}ms");
        } catch (Exception ex) {
            Console.WriteLine($"Faile: {ex.Message},_track:{ex.StackTrace}");
        }

Expected behavior

After upgrading the project to ef10, this issue occurred So I created a console program to test, and when the Microsoft. Data. SQL Client version was 5. X, the connection time was about 200ms. After upgrading to 6. x, this error occurred I developed it in a company environment, and my colleague pulled my branch without this issue, so it may be a problem with my local environment But I want to know where the problem lies

Further technical details

Microsoft.Data.SqlClient version: (6.1.4)
.NET target: (.NET 10.0)
Operating system: (Windows 10 Enterprise 1909)

[cape1999]

I tried to change the Connect Timeout to 30 seconds, and now my console program can open the connection normally, but it took 9157ms, which is obviously abnormal because in version 5. x, it only takes 200ms

[JuergenAuer]

Hi @cape1999

sometimes these are DNS errors. May be your environment has a configuration, so the DNS resolution doesn't work in the first step.

Check, if you can use the ip directly in your connection string.

[cape1999]

Hi @cape1999

sometimes these are DNS errors. May be your environment has a configuration, so the DNS resolution doesn't work in the first step.

Check, if you can use the ip directly in your connection string.

Thank you for your reply. Yes, I am currently using the IP address directly in the connection string. I can connect successfully using this IP and account via SSMS or SQLClient version 5.x. However, the issue only occurs after upgrading to version 6.x.

[apoorvdeshmukh]

@cape1999 Can you try version 6.0.5 for your console app? Please let us know the time it takes for connection to establish in comparison to 5.x

[ErikEJ]

@apoorvdeshmukh With a 5 second connect timeout, it looks like this: #3929

[apoorvdeshmukh]

@ErikEJ Yeah. This issue seems similar to #3523.

[cape1999]

@cape1999您能否尝试一下主机应用程序的6.0.5版本？请告知我们与 5.x 版本相比，连接建立所需的时间有何不同。

Microsoft.Data.SqlClient 6.1.4:
Success，Time: 9167ms
Microsoft.Data.SqlClient 6.0.5:
Success，Time: 127ms
Microsoft.Data.SqlClient 5.2.2(my first version):
Success，Time: 252ms
Microsoft.Data.SqlClient 6.1.1(first 6.1.x):
Success，Time: 9311ms

There seems to be a clue to the problem. The 6.1. x version seems to have modified something that conflicts with my network environment What more tests do I need to assist you with

[cape1999]

I opened the managed networking mode according to # 3523 and the issue was resolved in version 6.1.4, which seems to be a problem

[apoorvdeshmukh]

Hi @cape1999 Thank you for the response. You are indeed running into #3523 and this has been addressed in #3929.
The next hotfix release for 6.1.X should contain this fix.