[hem777]

> there was a period of time where i observed v as blue, right? that observation was invalid.

Not invalid. The observation was correct at that time and place, meaning, in the partition that it was observed. This is the P in AP.

It seems to me that you’re talking about and arguing for synchronization, that is, consensus about the values (=state), which takes the system to CP as opposed to AP.

> there is no straightforward way to module "a value"

I would recommend to look into the “Register” (CR)data structure.

[preseinger]

there is no single definition of a crdt "register"

i know this because i've implemented many versions of crdt "registers", with different properties, at scale

there are lww registers and multi-value registers, the former provides deterministic (but arbitrary) conflict resolution which loses information, the latter provides deterministic and non-arbitrary conflict resolution without losing information but with a more complex API

> The observation was correct at that time and place, meaning, in the partition that it was observed. This is the P in AP.

this is not what partition means

partition means that different subsets of nodes in a single system have different views on reality

if v=blue was true only during a partition, and is no longer represented in the history of v when the partition heals, then this value is not legal, violates serializability, is incorrect, etc.

https://jepsen.io/consistency#consistency-models

this has nothing to do with synchronization

[hem777]

> there are lww registers and multi-value registers

Use a single value register then in place where I said “register”.

> partition means that different subsets of nodes in a single system have different views on reality

Partition means that nodes of a (single) network are (temporarily) not connected.

In the example discussed here, blue and green were in different partitions thus had “different view” to the state. Once synchronized, their view on the state is consistent and both observe both values, blue being the latest state.

> is no longer represented in the history of v when the partition heals

Please review the above discussion again and the original article. You keep saying this but it’s shown in both that it’s is not true.

[preseinger]

"last writer wins" does not preserve state from losing (earlier) writers/writes

after synchronization, all nodes share a consistent view of state (yes) but that state has no history, it only contains the net final value (blue) as the singular and true state

this is not complicated, i think you're out of your element