I’m happy to announce a draft paper on our work on bringing LVar-style threshold reads to the setting of C(v)RDTs. In this paper, we define what it means for a CvRDT to support threshold reads, and we show that threshold reads of CvRDTs behave deterministically.
Determinism means something a little different in the distributed setting than it does in the shared-memory setting that we’re used to with LVars. The determinism property we show in the paper is: if a threshold query on a replica returns a particular result, then (1) subsequent runs of that query on that replica will always return that same result, and (2) any run of that query on any replica will eventually return that same result, and will block until it does so. (All this is under certain assumptions, of course, which we spell out in more detail in the paper.)