How to do Distributed Transactions XA in Spring and GlassFish 5?

Question

I am trying to create a transaction comprising two REST web services, whose data source point to the same data base. The first service, named 1, invokes another

Answer 1

rest web services (http based) are non-transactional by their nature (they are http based). you have made each method/operation transactional, but they do not share any state between the resources (rest operations). generally - you can have XA transactions over database or mesaging, not over http calls.

intRes2 = restTemplate.postForObject("http://localhost:8080/servicio2-1.0-
SNAPSHOT/servicio/2",numero,Integer.class);

Calling a remote web service is without any transaction context. If you need to maintains transaction between services, call the secord service as EJB (or as an injected managed bean)

Basically: using http-based rest services - forget any transactions between them. The protocol (HTTP) is not built for that.

The only thing I've seen transactional is SOAP with WS-RM extension (SOAP with reliable messaging)., however it is not very easy to setup (read: it can be nightmare to make it work when you don't know what are you doing) and not all WS frameworks support it.

When you really need reliable delivery between web services, there's a way. what is comonly used to achieve assured delivery is messaging with idempotent services (https://en.m.wikipedia.org/wiki/Idempotence) with store-and-forward pattern. In simple terms - service 1 stores a JMS message to a queue and there's a processor (MDB) which calls service 2. (yes, calling a remote web service it may happen that the service 2 will receive a message multiple times. Indempotency is a way how to deal with it.)