Consistency Model

each operation, $R$ : read, $W$: write, has invocation timestamp and response timestamp (start-end)

Data Centric Consistency Model

Strick Consistency(Linearizability)

1. every read $R$ return the values of the most recent $W$ in the sequence
2. if the response timestamp of operation 1 occurs before the invocation of operation 2, then op1 occurs before op2 in the sequence

Sequential Consistency

Counter Sequential consistency

R(x,0) must happens before W(x,4) because if R(x,0) happens after W(x,4), R(x) should be R(x,4)

Causal Consistency

Client Centric Consistency Model

Read-your-writes

Write-follow-reads

Monotonic-reads (Read after rEad)

Monotonic-writes (Write after wRite)