Suspicious nested transaction behaviour code

[sdedic]

Expected Behavior

A @Transactional(propagation = Transactional.Propagation.NESTED) should create a new transaction, if there's an existing one, according to the documentation of NESTED:

Execute within a nested transaction if a current transaction exists

Actual Behaviour

The existing transaction seems to be reused. See the relevant code in AbstractTransactionOperations

Steps To Reproduce

1. checkout demo app from https://github.com/sdedic/micronaut-dbbugs1
2. checkout branch nested-transaction
3. place a breakpoint on line in AbstractTransactionOperations
4. execute the application with parameter -3

No nested transaction is opened. Transaction closes with the outermost one.

Environment Information

• Ubuntu 22.04
• JDK 21

Example Application

No response

Version

4.7.6

[dstepanov]

It should create a new nested TX if one exists. Nested TX is pretty much just using snapshots.

Not every TX managers support nested TXs.

Execute within a nested transaction if a current transaction exists,
         * behave like {@link Propagation#REQUIRED} otherwise. There is no
         * analogous feature in EJB.
         * <p><b>NOTE:</b> Actual creation of a nested transaction will only work on
         * specific transaction managers. Out of the box, this only applies to JDBC
         * when working on a JDBC 3.0 driver. Some JTA providers might support
         * nested transactions as well.