ConnectionFailedException: The collection already contains item with same key 'net.transport'

[atiq-cs]

Software versions
MySqlConnector version:
bug exists in nuget package versions starting with '2.0.0-beta.5'.
Specifically, 2.0.0-beta.5' and '2.0.0-rc.1' repro this.

Server type (MySQL, MariaDB, Aurora, etc.) and version:
MySQL

.NET version: .Net 6
ORM NuGet packages and versions: 2.0.0-beta.5 and 2.0.0-rc.1

Describe the bug
starting with version 2.0.0-beta.5 connection is failing with MySQL server. It was working till 1.4.0-beta.4. It still works if I downgrade to 1.4.0-beta.4.

Exception

Unhandled exception ConnectionFailedException: "The collection already contains item with same key 'net.transport''"
 ---> System.InvalidOperationException: "The collection already contains item with same key 'net.transport''"
   at System.Diagnostics.ActivityTagsCollection.Add(String key, Object value)
   at MySqlConnector.Core.ServerSession.OpenTcpSocketAsync(ConnectionSettings cs, ILoadBalancer loadBalancer, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 1059
   at MySqlConnector.Core.ServerSession.ConnectAsync(ConnectionSettings cs, MySqlConnection connection, Int32 startTickCount, ILoadBalancer loadBalancer, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 422
   at MySqlConnector.Core.ConnectionPool.ConnectSessionAsync(MySqlConnection connection, String logMessage, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 363
   at MySqlConnector.Core.ConnectionPool.GetSessionAsync(MySqlConnection connection, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 94
   at MySqlConnector.Core.ConnectionPool.GetSessionAsync(MySqlConnection connection, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 124
   at MySqlConnector.MySqlConnection.CreateSessionAsync(ConnectionPool pool, Int32 startTickCount, Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 911
   at MySqlConnector.MySqlConnection.OpenAsync(Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 405
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+MoveNext() in D:\Code\wordpress-export\Goodbye.WordPress\MysqlPostReader.cs:line 51
   --- End of inner exception stack trace ---
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+MoveNext() in D:\Code\wordpress-export\Goodbye.WordPress\MysqlPostReader.cs:line 55
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()
   at Goodbye.WordPress.WordPressExporter.ExportAsync(CancellationToken cancellationToken) in D:\Code\wordpress-export\Goodbye.WordPress\WordPressExporter.cs:line 162
   at Goodbye.WordPress.WordPressExporter.ExportAsync(CancellationToken cancellationToken) in D:\Code\wordpress-export\Goodbye.WordPress\WordPressExporter.cs:line 162
   at Program.<Main>$(String[] args) in D:\Code\wordpress-export\Export\Program.cs:line 18
   at Program.<Main>(String[] args)

Code sample
https://github.com/abock/goodbye-wordpress/blob/master/Goodbye.WordPress/MysqlPostReader.cs#L51

string? originalPermalinkStructure = null;

using var connection = new MySqlConnection(ConnectionString);

try
{
    await connection.OpenAsync(cancellationToken);
}
catch (Exception e)
{
    throw new ConnectionFailedException(e);
}

Expected behavior
runs without exception and no error with old versions. I am expecting same behavior with new versions of MySqlConnector

[bgrainger]

Does your connection string contain multiple host names?

[bgrainger]

There's a retry loop for SSL; it seems possible that this error could occur if the first TLS handshake (for TLS 1.2) fails and the client tries again.

[bgrainger]

I was able to reproduce this by connecting to a server that only supports TLS 1.1; the exception is thrown when internally retrying the connection.

You should be able to work around it by adding ; TLS Version = TLS 1.1 to your connection string.

Thanks for reporting the problem!

[atiq-cs]

I see what you mean. Thanks for the hint.

My problem is solved. I am adding some testing results, just, for the record.

Tls Version 1.1 doesn't work with this mysql database server we are using. 1.0 works for this one. So, I appended following with the connection string,

";TlsVersion=TLS 1.0";

I tried few things with the database server (MySqlConnector version 2.0.0-rc.1). I found following,

• version 2.0.0-rc.1 seems to use TLS 1.2 by default which generated the error in bug description.
• If I pass 1.3 I get slightly different error which is below,

$ dotnet run
Unhandled exception. Goodbye.WordPress.ConnectionFailedException: SSL Authentication Error
 ---> MySqlConnector.MySqlException (0x80004005): SSL Authentication Error
 ---> System.Security.Authentication.AuthenticationException: Authentication failed, see inner exception.
 ---> System.ComponentModel.Win32Exception (0x80090331): The client and server cannot communicate, because they do not possess a common algorithm.
   --- End of inner exception stack trace ---
   at System.Net.Security.SslStream.ForceAuthenticationAsync[TIOAdapter](TIOAdapter adapter, Boolean receiveFirst, Byte[] reAuthenticationData, Boolean isApm)
   at MySqlConnector.Core.ServerSession.InitSslAsync(ProtocolCapabilities serverCapabilities, ConnectionSettings cs, MySqlConnection connection, SslProtocols sslProtocols, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 1418
   at MySqlConnector.Core.ServerSession.InitSslAsync(ProtocolCapabilities serverCapabilities, ConnectionSettings cs, MySqlConnection connection, SslProtocols sslProtocols, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 1461
   at MySqlConnector.Core.ServerSession.ConnectAsync(ConnectionSettings cs, MySqlConnection connection, Int32 startTickCount, ILoadBalancer loadBalancer, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 485
   at MySqlConnector.Core.ConnectionPool.ConnectSessionAsync(MySqlConnection connection, String logMessage, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 363
   at MySqlConnector.Core.ConnectionPool.GetSessionAsync(MySqlConnection connection, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 94
   at MySqlConnector.Core.ConnectionPool.GetSessionAsync(MySqlConnection connection, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 124
   at MySqlConnector.MySqlConnection.CreateSessionAsync(ConnectionPool pool, Int32 startTickCount, Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 911
   at MySqlConnector.MySqlConnection.OpenAsync(Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 405
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+MoveNext() in D:\Code\wordpress-export\Goodbye.WordPress\MysqlPostReader.cs:line 51
   --- End of inner exception stack trace ---
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+MoveNext() in D:\Code\wordpress-export\Goodbye.WordPress\MysqlPostReader.cs:line 55
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()
   at Goodbye.WordPress.WordPressExporter.ExportAsync(CancellationToken cancellationToken) in D:\Code\wordpress-export\Goodbye.WordPress\WordPressExporter.cs:line 162
   at Goodbye.WordPress.WordPressExporter.ExportAsync(CancellationToken cancellationToken) in D:\Code\wordpress-export\Goodbye.WordPress\WordPressExporter.cs:line 162
   at Program.<Main>$(String[] args) in D:\Code\wordpress-export\Export\Program.cs:line 18

When I try TLS Version 1.1 I get following,

Unhandled exception. Goodbye.WordPress.ConnectionFailedException: The server doesn't support the client's specified TLS versions.
 ---> MySqlConnector.MySqlException (0x80004005): The server doesn't support the client's specified TLS versions.
 ---> System.ComponentModel.Win32Exception (0x80090331): The client and server cannot communicate, because they do not possess a common algorithm.
   at System.Net.SSPIWrapper.AcquireCredentialsHandle(ISSPIInterface secModule, String package, CredentialUse intent, SCH_CREDENTIALS* scc)
   at System.Net.Security.SslStreamPal.AcquireCredentialsHandle(CredentialUse credUsage, SCH_CREDENTIALS* secureCredential)
   at System.Net.Security.SslStreamPal.AcquireCredentialsHandleSchCredentials(X509Certificate2 certificate, SslProtocols protocols, EncryptionPolicy policy, Boolean isServer)
   at System.Net.Security.SslStreamPal.AcquireCredentialsHandle(SslStreamCertificateContext certificateContext, SslProtocols protocols, EncryptionPolicy policy, Boolean isServer)
   at System.Net.Security.SecureChannel.AcquireClientCredentials(Byte[]& thumbPrint)
   at System.Net.Security.SecureChannel.GenerateToken(ReadOnlySpan`1 inputBuffer, Byte[]& output)
   at System.Net.Security.SecureChannel.NextMessage(ReadOnlySpan`1 incomingBuffer)
   at System.Net.Security.SslStream.ForceAuthenticationAsync[TIOAdapter](TIOAdapter adapter, Boolean receiveFirst, Byte[] reAuthenticationData, Boolean isApm)
   at MySqlConnector.Core.ServerSession.InitSslAsync(ProtocolCapabilities serverCapabilities, ConnectionSettings cs, MySqlConnection connection, SslProtocols sslProtocols, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 1418
   at MySqlConnector.Core.ServerSession.InitSslAsync(ProtocolCapabilities serverCapabilities, ConnectionSettings cs, MySqlConnection connection, SslProtocols sslProtocols, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 1465
   at MySqlConnector.Core.ServerSession.ConnectAsync(ConnectionSettings cs, MySqlConnection connection, Int32 startTickCount, ILoadBalancer loadBalancer, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 485
   at MySqlConnector.Core.ConnectionPool.ConnectSessionAsync(MySqlConnection connection, String logMessage, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 363
   at MySqlConnector.Core.ConnectionPool.GetSessionAsync(MySqlConnection connection, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 94
   at MySqlConnector.Core.ConnectionPool.GetSessionAsync(MySqlConnection connection, Int32 startTickCount, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ConnectionPool.cs:line 124
   at MySqlConnector.MySqlConnection.CreateSessionAsync(ConnectionPool pool, Int32 startTickCount, Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 911
   at MySqlConnector.MySqlConnection.OpenAsync(Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 405
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+MoveNext() in D:\Code\wordpress-export\Goodbye.WordPress\MysqlPostReader.cs:line 51
   --- End of inner exception stack trace ---
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+MoveNext() in D:\Code\wordpress-export\Goodbye.WordPress\MysqlPostReader.cs:line 55
   at Goodbye.WordPress.MysqlPostReader.ReadPostsAsync(CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()
   at Goodbye.WordPress.WordPressExporter.ExportAsync(CancellationToken cancellationToken) in D:\Code\wordpress-export\Goodbye.WordPress\WordPressExporter.cs:line 162
   at Goodbye.WordPress.WordPressExporter.ExportAsync(CancellationToken cancellationToken) in D:\Code\wordpress-export\Goodbye.WordPress\WordPressExporter.cs:line 162

[bgrainger]

version 2.0.0-rc.1 seems to use TLS 1.2 by default

So do earlier versions of MySqlConnector; it's just that before #1037 the internal retry loop (to downgrade TLS versions) didn't cause the exception you were seeing (but it was still happening).