MySQL Bugs: #116146: OpenAsync (of MySqlConnection) throws exception when UseCompression = true

Bug #116146	OpenAsync (of MySqlConnection) throws exception when UseCompression = true
Submitted:	18 Sep 2024 13:16	Modified:	27 Apr 14:44
Reporter:	Yitzhak Shmuel	Email Updates:
Status:	Verified	Impact on me:	None
Category:	Connector / NET	Severity:	S3 (Non-critical)
Version:	9.3.0	OS:	Windows (Windows 10 Enterprise)
Assigned to:	Assigned Account	CPU Architecture:	Any

Description:
Hi,

When calling the OpenAsync method of MySqlConnection, when the UseCompression of MySqlConnectionStringBuilder is set to true, a "EndOfStreamException: Attempted to read past the end of the stream" exception is thrown.

Using the Open method instead of the OpenAsync method works as expected.
Also, setting the UseCompression to false works as expected as well.

I'm using VS2022, dotnet 8, MySql.Data nuget package, version 9.0.0.

Thanks

How to repeat:
using MySql.Data.MySqlClient;

internal class Program
{
    private static async Task<int> Main(string[] args)
    {        
        var cancellationToken = new CancellationToken();
        var mySqlConnectionStringBuilder = new MySqlConnectionStringBuilder
        {          
            UserID = "userid", Password = "pass", Server = "server", Port = 3306, Database = "db",
            UseCompression = true
        };

        await using (var dbConnection = new MySqlConnection(mySqlConnectionStringBuilder.ConnectionString))
        {
            await dbConnection.OpenAsync(cancellationToken);
            await using (MySqlCommand queryCommand = new MySqlCommand("SELECT 1", dbConnection))
            {
                var res = await queryCommand.ExecuteNonQueryAsync(cancellationToken);
            }
        }

        return 0;
    }
}

Hi Mr. Shmuel,

Please also read the following chapter from our manual:

https://dev.mysql.com/doc/refman/9.0/en/connection-compression-control.html

It should be quite useful to you .....

Hi,

Thanks for your response. 
Unfortunately I have no knowledge in C or Phyton, and a very limited time to try to perform the experiment that you suggested with those packages.
I'll wait for the release of 9.0.1 and see if the issue was resolved.

Thanks,
Yitzhak Shmuel

Hi Mr. Shmuel,

We shall wait on your feedback.

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".

Tested Connector/NET 9.1.0 from NuGet.  Verified something is not right when usding compression.

On my system, the compressed connection hangs.
Disabling compression works fine.  SSL had no impact.

I even changed the code to be:

var dbConnection = new MySqlConnection(mySqlConnectionStringBuilder.ConnectionString);
await dbConnection.OpenAsync(cancellationToken);
MySqlCommand queryCommand = new MySqlCommand("SELECT 1", dbConnection);
var res = await queryCommand.ExecuteNonQueryAsync(cancellationToken);

-- 
Shane, MySQL Senior Principal Technical Support Engineer
Oracle Corporation
http://dev.mysql.com/

Hi, The problem still exists in 9.1.0, Thanks

MySql.Data9.2.0 - exception and stack trace

Attachment: MySql.Data.9.2.0-ExceptionStackTrace.png (image/png, text), 52.04 KiB.

Hi, 

The problem still occurs in version 9.2.0.
I'm getting "Fatal error encountered during command execution" with this version.
I attached a screenshot of the exception and the stack trace.

I used the same code as before for the testing.

Thanks

Hi,

The issue still persists in 9.3.0.
It would be great if someone could take a look at this.

Thanks,
Itzik