'The session is not open' in ListDirectoryAsync

[m0a0k0s]

On rare occasions, I see 'The session is not open' in ListDirectoryAsync.
The last time I saw it, it was for a server where multiple instances of sftpClient might get created simultaneously with the same username/password, but working with different folders.

SSH.NET 2025.1.0 .Net 9.

My code looks like this:

try
{
    await sftpClient.ConnectAsync(cancellationToken);
	
    await sftpClient.ChangeDirectoryAsync(path, cancellationToken);
    var asyncList = sftpClient.ListDirectoryAsync(path, cancellationToken);
}
finally
{
	if (sftpClient.IsConnected)
		sftpClient.Disconnect();
}

"Type": "System.InvalidOperationException",
"HResult": -2146233079,
"Message": "The session is not open.",
"Source": "Renci.SshNet",
"StackTrace": " at Renci.SshNet.Sftp.SftpSession.SendRequest(SftpRequest request)\r\n at Renci.SshNet.Sftp.SftpSession.GetCanonicalPathAsync(String path, CancellationToken cancellationToken)\r\n at Renci.SshNet.SftpClient.ListDirectoryAsync(String path, CancellationToken cancellationToken)+MoveNext()\r\n at Renci.SshNet.SftpClient.ListDirectoryAsync(String path, CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource.GetResult()",
"TargetSite": "Void SendRequest(Renci.SshNet.Sftp.Requests.SftpRequest)"

[mus65]

In your example, the asyncList is not being enumerated, so you are basically disconnecting while ListDirectoyAsyncis still running in the background.

[JuergenAuer]

Hi @m0a0k0s

The last time I saw it, it was for a server where multiple instances of sftpClient might get created simultaneously with the same username/password, but working with different folders.

how many connections are created if you see "multiple instances"? The server may have a maximum of allowed connections. So if you create too much connections, the server may close some of the connections.

May be you should change your design to use only one connection ... and the problem may dissapear.