Java Spring - 如何保持 2 个数据库/2 个微服务一致 state

Question

I have the following task to do: when new item is saved in first (main) microservice , I should use API froms second microservice and save the same item in other database that is managed by my first microservice. The question is what in case when an attempt to save item in database from second microservice will end up with fail? I want to have consistent databases: when data are saved in db 1 (first microservice), should be also saved in db 2 (second microservice) or shouldn't be saved anywhere.

1. I have controller:

    @PostMapping(path = "store", consumes = "application/json")
    @ResponseStatus(value = HttpStatus.CREATED)
    public IdDto createStore(Authentication auth, @RequestBody StoreDto storeDto,
                                 BindingResult bindingResult) {

...
Authorization identity = authenticationService.getIdentity(auth);
Store store = commandBus.execute(new CreateStoreCommand(storeDto, details));
...
}

2.Command is sent and handler handles my command:

public class CreateStoreCommandHandler implements CommandHandler<Store, CreateStoreCommand> {
   @Override
    public Store handle(CreateStoreCommand command) {
        ...
        Store store = createStore(...)
        return storeService.save(store);
}

3. StoreService:

public class StoreService {
 @Transactional
    public Store save(@NonNull Store store) {
        
        Store savedStore = storeRepository.save(store);
        publisher.publishEvent(PushEvent.created(savedStore));
        return savedStore;
    }
}

4. I have to use API to save my object in other service/other database, below is my service that saves data in second microservice

public class SecondMicroserviceService {
 public void saveStore(long xUserId, StoreDto store) {
        try {
            newMicroserviceApi.saveStore(xUserId, store)
                    .firstOrError()
                    .retry(RetrofitUtils.bailOnDurableErrorPredicate(retryAttempts))
                    .blockingGet();
        } catch (HttpException ex) {
            RetrofitUtils.on404Return(ex, Optional.empty());
        }
    }
}

My questions: How to handle such a situation? Should I call method SecondMicroserviceService.saveStore in StoreService inside a method:

@Transactional
    public Store save

? And that's it?

I know that distributed transactions across microservices should be avoided and we should use @Transactional(propagation = Propagation.NEVER)

Answer 1

On the first commit from your micro service A why don't you make a Feign call to another micro service to execute the update? Or if you have a queuing to make it async then post it to micro service attached queue?