No rollback with quarkus, mutiny and reactive postgresql

Question

I am trying to get 3 inserts executed within the same transaction, but I am not able to get the transaction rolled back when one of the inserts fail.

I am new in the reactive world and this is my very first reactive application.

Here is a simplification of the database model:

EntityA 1---N EntityB
EntityA 1---N EntityC

I want to execute the following inserts within the same transaction:

INSERT INTO A
INSERT INTO B  --(failing query)
INSERT INTO C

But, when the second insert fails, the first insert does not rollback.

I've got the following classes:

• Processor: receives a message from kafka and triggers the inserts though a Service
• Service: runs the 3 inserts by using 3 DAOs
• EntityADao: runs the insert of the entity A
• EntityBDao: runs the insert of the entity B
• EntityBDao: runs the insert of the entity C

@ApplicationScoped
public class Processor {
    private final Service service;

    public Processor(final Service service) {
        this.service = service;
    }

    @Incoming("input-channel")
    @Outgoing("output-channel")
    public Uni<Message<RequestMessage>> process(final Message<RequestMessage> message) {
        final RequestMessage rm = message.getPayload();

        return service.saveEntities(rm)
                .onFailure()
                    .recoverWithItem(e -> {
                        final String errorMessage = "There was an unexpected error while saving entities";
                        LOG.error(errorMessage, e);

                        return Result.KO;
                    })
                .flatMap(result -> {
                    rm.setResult(result);

                    return Uni.createFrom()
                        .item(Message.of(rm), message::ack))
                });
    }
}

@ApplicationScoped
public class WorkerService {
    private final EntityADao entityADao;
    private final EntityBDao entityBDao;
    private final EntityCDao entityCDao;

    public WorkerService(final EntityADao entityADao,
                         final EntityBDao entityBDao,
                         final EntityCDao entityCDao) {
        this.entityADao = entityADao;
        this.entityBDao = entityBDao;
        this.entityCDao = entityCDao;
    }

    @Transactional(TxType.REQUIRED)
    public Uni<Result> saveEntities(final RequestMessage requestMessage) {
        return Uni.createFrom().item(Result.OK)
                // Save Entity A
                .flatMap(result -> {
                    LOG.debug("(1) Saving EntityA ...");

                    return entityADao.save(requestMessage.getEntityAData());
                })
                // Save Entity B
                .flatMap(result -> {
                    LOG.debug("(2) Saving EntityB ...");

                    return entityBDao.save(requestMessage.getEntityBData());
                })
                // Save Entity C
                .flatMap(result -> {
                    LOG.debug("(3) Saving EntityC ...");

                    return entityCDao.dao(requestMessage.getEntityCData());
                })
                // Return OK
                .flatMap(result -> Uni.createFrom().item(Result.OK));
    }
}

@ApplicationScoped
public class EntityADao {
    private final PgPool client;

    public EntityADao(final PgPool client) {
        this.client = client;
    }

    @Transactional(TxType.MANDATORY)
    public Uni<Result> save(final EntityAData entityAData) {
        return client
                .preparedQuery(
                        "INSERT INTO A(col1, col2, col3) " +
                            "VALUES ($1, $2, $3)")
                .execute(Tuple.of(entityAData.col1(), entityAData.col2(), entityAData.col3()))
                .flatMap(pgRowSet -> {
                    LOG.debug("Inserted EntityA!");

                    return Result.OK;
                });
    }
}

EntityBDao and EntityCDao are like EntityADao.

I have already added the following dependencies to pom.xml:

• quarkus-smallrye-context-propagation
• quarkus-narayana-jta

Why when the INSERT B query in EntityBDao fails, the previously executed query (INSERT A) does not rollback? What do am I missing? What would I have to change in order to get this working?

Answer 1

This paragraph recently added to our Quarkus documentation should help you with this: https://quarkus.io/guides/reactive-sql-clients#transactions .

It specifically explains how to deal with transactions when using the Reactive SQL clients.