JTA with reactive Panache not working properly?

[paloliska]

Hi,

I was looking into io.quarkus.mongodb.panache.common.reactive.Panache.withTransaction(..) method:

Panache.startSession()
                    .invoke(s -> s.startTransaction())
                    .invoke(s -> context.putLocal(SESSION_KEY, s))
                    .chain(s -> work.get())
                    .call(() -> commitTransaction())
                    .onFailure().call(() -> abortTransaction())
                    .eventually(() -> Panache.closeSession());

There as you can see we are waiting for work to be done, than is called commitTransaction().
However commitTransaction() is uni with no subscriber as following:

private static Uni<?> commitTransaction() {
        Context context = vertxContext();
        ClientSession current = context.getLocal(SESSION_KEY);
        return toUni(current.commitTransaction());
    }

Does this means that this commitTransaction uni is not guaranteed to be run exactly after work? We are subscribed to uni Panache.startSesstion(), but not to uni commitTransaction().

Are my thoughts correct?

[quarkus-bot[bot]]

/cc @FroMage (panache), @loicmathieu (panache)

[loicmathieu]

Hi,

No, sorry, but the code is correct not your thoughts ;)

call() like all other operation on Uni returns a new Uni, all operations are inside the chain of Unis which will be resolved by Quarkus as long as you subscribe to the last Uni in the chain. You usually subscribe to it by returning it to the Quarkus runtime (inside a REST endpoint for example).

The commitTransaction method returns a Uni that will be passed to the chain of Unis by the call() method.