[ickyforce]

> So unless those pools are full of primitive data types, you’re going to cause more frequent full GC pauses, and longer due to all the back pointers.

If you have enough objects pooled to get low allocation rate then you never trigger full GC. That's what "low latency Java" aims for.

I think that the main downside of object pools in Java is that it's very easy to accidentally forget to return an object to a pool or return it twice. It turns out that it's hard to keep track of what "owns" the object and should return it if the code is not a simple try{}finally{}. This was a significant source of bugs at my previous job (algo trading).

[hinkley]

You only get low full GC as long as the entire app makes no allocations, not just the hot path. If you allocate garbage at all eventually you will trigger one.