When using a transactional cache with ATTRIBUTE granularity, the following code will trigger a redundant cache operation upon request completion:

[1]
AtomicInteger value = (AtomicInteger) session.getAttribute("a");
value.incrementAndGet();
session.setAttribute("a", value);

[2]
session.setAttribute("a", new AtomicInteger());
AtomicInteger value = (AtomicInteger) session.getAttribute("a");
value.incrementAndGet();

In case [1], the initial mutable getAttribute(...) triggers an eager mutate, which becomes redundant by the subsequent setAttribute(...).
In case [2], the subsequent mutable getAttribute(...) does not need to trigger a mutation, as the previous setAttribute(...) already has.