KeyNotFoundException in MySqlBulkLoader.GetAndRemoveStream()

[wangjia184]

When loading a streaming into a table, MySqlBulkLoader.LoadAsync() may fail with KeyNotFoundException

  at System.ThrowHelper.ThrowKeyNotFoundException[T](T key)
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at MySql.Data.MySqlClient.MySqlBulkLoader.GetAndRemoveStream(String streamKey) in C:\projects\mysqlconnector\src\MySqlConnector\MySql.Data.MySqlClient\MySqlBulkLoader.cs:line 241
   at MySql.Data.MySqlClient.MySqlBulkLoader.<LoadAsync>d__80.MoveNext() in C:\projects\mysqlconnector\src\MySqlConnector\MySql.Data.MySqlClient\MySqlBulkLoader.cs:line 207
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()

My code:

                MySqlBulkLoader loader = new MySqlBulkLoader(conn);
                loader.TableName = "tournament_result";
                loader.FieldTerminator = DataFileGenerator.FIELDS_TERMINATER;
                loader.EscapeCharacter = '\b';
                loader.LineTerminator = DataFileGenerator.LINES_TERMINATER;
                loader.Columns.Add("ID");
                loader.Columns.Add("UserID");
                loader.Columns.Add("Score");
                loader.Columns.Add("Rank");
                loader.Columns.Add("Comments");
                loader.Timeout = 60 * 5;
                loader.Local = true;
                loader.ConflictOption = MySqlBulkLoaderConflictOption.Replace;
                using (loader.SourceStream = generator.GetStream())
                {
                    await loader.LoadAsync().ConfigureAwait(false);
                }

The reason is that, when ExecuteNonQueryAsync fails, closeStream is not set to false but the key does not exist in s_sources.

KeyNotFoundException is raised in the finally block when calling GetAndRemoveSource

MySqlConnector/src/MySqlConnector/MySql.Data.MySqlClient/MySqlBulkLoader.cs

Line 209 in bec3544

((IDisposable) GetAndRemoveSource(FileName!)).Dispose();

[bgrainger]

The reason is that, when ExecuteNonQueryAsync fails

Your original exception is probably being overwritten by the KeyNotFoundException, but can you explain how or why the original failure is occurring during the bulk load?

[wangjia184]

The supplied stream contains NULL but quotation is not used hence it cannot be recognized.

Anyway, because the exception is overridden in finally block, it makes harder to locate the issue.

[bgrainger]

Fixed in 0.62.0.