Null Reference Exception when the TransactionScope exits from the scope

[federicoorlandini]

I'm using Npgsql 3.0.3 and a PostgreSQL server 9.3 and I'm trying to use a distributed transaction to orchestrate some data movement between two different database servers.
The code I'm using the the following:

using (var sourceDbConnection = new NpgsqlConnection(SourceConnectionString))
using (var destinationDbConnection = new NpgsqlConnection(DestinationConnectionString))
using (var scope = new TransactionScope())
    {
        sourceDbConnection.Open();
        destinationDbConnection.Open();

        Logger.Info("Moving data for the {0} table.", TableName.ToUpper());
        var innerStopWatch = new Stopwatch();
        innerStopWatch.Start();

        foreach (var entity in entities)
        {
            var etlEntity = new EtlInfoItem
            {
                MigratedEntityId = category.RowId,
                ProjectId = category.ProjectId,
                ExecutionDatetime = DateTime.Now
            };

            // Insert into the destination database
            var isRowMigrated = InsertEntity(entity, DestinationSchema, destinationDbConnection);

            if (isRowMigrated)
            {
                // Update the ETL migration table
                InsertCompletedEtlMigrationEntity(etlEntity, EtlSchema, sourceDbConnection);
            }
            else
            {
                // Update the ETL migration table
                InsertFailedEtlMigrationEntity(etlEntity, EtlSchema, sourceDbConnection);
            }
        }

        Logger.Info("Data moved in {0} sec.", innerStopWatch.Elapsed);

        Logger.Info("Committing transaction to the source database");
                innerStopWatch.Restart();

        scope.Complete();

        innerStopWatch.Stop();
        Logger.Info("Transaction committed in {0} sec.", innerStopWatch.Elapsed);
    }

When the TransactionScope exits from the scope (when exiting the using statement), I get a Null Reference Exception with the following stack trace:
Server stack trace:
at Npgsql.NpgsqlConnector.Cleanup()
at Npgsql.NpgsqlConnector.Break()
at Npgsql.NpgsqlConnector.ReadSingleMessage(DataRowLoadingMode dataRowLoadingMode, Boolean returnNullForAsyncMessage)
at Npgsql.NpgsqlConnector.ReadExpectingT
.........
It happens randomly.

[roji]

@damageboy, want this?

[roji]

SO link: http://stackoverflow.com/questions/33588232/does-npgsql-provider-has-support-for-transactionscope/33592757

[roji]

@damageboy do you want to take a look at this?

[roji]

I'm really sorry this hasn't received an answer sooner. I'm hard at work preparing 3.1 for a beta release and won't be able to look at this soon. However, one of 3.2's major goals is a cleanup of how distributed transactions work, and this will be definitely be taken care of.

[roji]

Am finally getting around to work on System.Transactions support - am pretty much rewriting the whole thing to be safer and simpler. A lot has changed regardless in Npgsql since this issue was opened, so I'm going to close it. If you can help test the upcoming 3.2, you should be able to grab recent 3.2 CI nugets from the unstable feed, or you can wait until a beta is released (hopefully not too long from now).

If you encounter the same issue with these new versions, please post back here and I'll reopen.