Connection timeout if MySqlDataReader isn't disposed

[bgrainger]

The following code will eventually throw a MySqlConnection "Connect Timeout expired" and leave the pool full of idle but unusable sessions.

while (true)
{
	var connection = new MySqlConnection(csb.ConnectionString);
	connection.Open();
	var cmd = connection.CreateCommand();
	cmd.CommandText = "SELECT 1";
	var reader = cmd.ExecuteReader();
        while (reader.Read()) { }

        GC.Collect(); // to try to force objects to be cleaned up
}

In MySqlConnector, this happens because there's a strong reference from MySqlSession to MySqlCommand and MySqlDataReader, and from those to MySqlConnection, so the WeakReference-based code never works.

This also fails in MySql.Data, so it's not a new bug. However, it would be nice to fix it so that "invalid" use of the library doesn't make connection pools unusable.

[nvivo]

This looks a lot like what is happening here. A some points during the day, I have these sudden bursts of mysql exceptions saying "Connect Timeout expired". I thought they were due to more connections being open with real async and the idle connections filling up the pool, but if that is the case, a GC happening at a very specific time could be cause this too.

[bgrainger]

Fixed in 0.24.1.

@nvivo Please test your scenario again with this new build (once it's available on NuGet, hopefully in a few minutes).