Modifying domain objects results in error - 50% of the time

Question

I created a fresh grails 5.1.2 project, installed spring-security (directly, not via plugin) and installed grails-spring-websocket:2.5.0.RC1.

It seemed that everything works fine until I started to modify domain objects within a websocket controller:

@MessageMapping("/edit")
@SendTo("/topic/result")
protected String edit(String message) {
  Book.withTransaction {
    def book = Book.findByName("Book1")
    book.pages += 1
    book.save(flush: true)
  }
}

This snippet it part of the Book-controller. I added the .withTransaction part when I got error messages telling me that there is no hibernate session.

Now, the result is somehow random. The code works sometimes and sometimes I get an error message saying

Batch update returned unexpected row count from update [0]

any help would be highly appreciated :-)

Answer 1

ok, I was searching in the wrong place:

my application gets lots of messages for the same domain object. All those messages try to change the same property at the same time.

I will now change my data structure to fit.