[bluejekyll]

While I agree that CRDTs could work here, what struck me is you comment about a “regular-old timestamp”. In distributed systems, this isn’t simple. In fact, Lamport Clocks are a specific solution to guaranteeing a consistent monotonically increasing clock such that one time is known to occur after the other. A single instance, or primary db, can provide this, but in distributed systems this is the primary problem. There is no “regular-old timestamp” in distributed systems.

[MattPalmer1086]

Right. You can't guarantee clocks in a distributed system are synchronised, unless you control all the nodes. Lamport clocks don't use time, they work on causal order. This came after that, not this happened at a particular time.

[CGamesPlay]

Definitely true. In this case, where nodes are browsers (so clocks can easily be synced to within a few seconds of one another) and changes are user settings (so they change less than once an hour), a last-write-wins register seems like a great choice for an atomic setting like a boolean.

For settings where we can more intelligently handle conflicts (e.g. sets), we don't need the timestamps, because we can take advantage of vector clocks instead.