[FIXED] Spring Data Neo4j OGM version and transaction isolation/propagation

Issue

I have a service method mergeAndUpdateAndCompliance() which uses Spring Data Neo4j OGM version:

@Transactional("neo4jTransactionManager")
@Override
public ComplianceMatrix mergeAndUpdateAndCompliance() {

        mergeAndUpdate();

        return compliance()
}


@Override
public void mergeAndUpdate() {
  //do some update operations
}

@Override
@Transactional(readOnly = true, transactionManager = "neo4jTransactionManager")
public void compliance() {
  //do some read operations
}

mergeAndUpdateAndCompliance() invokes two other service methods - mergeAndUpdate() and compliance(). compliance() reads the data updated by mergeAndUpdate(). Right now compliance() doesn't see the data updated in mergeAndUpdate() in the same transaction.

It works only if I add session.getTransaction().commit(); between them:

@Autowired
private Session session;

@Transactional("neo4jTransactionManager")
@Override
public ComplianceMatrix mergeAndUpdateAndCompliance() {

        mergeAndUpdate();

        session.getTransaction().commit();

        return compliance()
}

Is it safe to place session.getTransaction().commit(); inside of Spring transaction ? What is the right way to solve this issue? Is it possible to use transaction propagation with SDN in order to configure mergeAndUpdate with REQUIRES_NEW ?

Solution

You have applied @Transactional on the mergeAndUpdateAndCompliance, function, within it is also applied to compliance method. You should try this way:

@Override
public ComplianceMatrix mergeAndUpdateAndCompliance() {
        mergeAndUpdate();
        return compliance()
}


@Override
@Transactional("neo4jTransactionManager")
public void mergeAndUpdate() {
  //do some update operations
}

@Override
@Transactional(readOnly = true, transactionManager = "neo4jTransactionManager")
public void compliance() {
  //do some read operations
}

Instead of applying it on the mergeAndUpdateAndCompliance, you should apply it on mergeAndUpdate and compliance functions separately. So that you don't have to manually commit the transaction.

Answered By - Charchit Kapoor
Answer Checked By - David Goodson (JavaFixing Volunteer)