Method — State Consistency

Definition, scope boundary, and structural model.

Definition

State Consistency refers to the condition in which relevant state representations or observations satisfy a defined consistency constraint or guarantee.

Model Classification

Consistency constraint model.

Scope Boundary

Included

State representations whose consistency is evaluated
Consistency requirements and guarantees
Relationships among corresponding or relevant states
Permissible state divergence where allowed by the applicable consistency model
State convergence where required by the applicable consistency model
Consistency of observations of system state
Consistency models insofar as they define applicable state guarantees

Excluded

State synchronization as such
Replication mechanisms as such
Consensus protocols
Quorum mechanisms
Conflict-resolution mechanisms
State-machine replication as a specific implementation approach
Transaction processing generally
ACID consistency as the universal definition
State equality as a universal requirement
Convergence as a universal requirement
Availability or partition tolerance as definitions of State Consistency

State Consistency Structure Model

State Representation

A state or observable representation of system information whose consistency is evaluated relative to another relevant state, representation, or observation.

Consistency Constraint

The requirement or guarantee that defines which relationships, observations, or divergences among relevant state representations are permitted.

Consistency Condition

The condition in which the relevant state representations or observations satisfy the applicable consistency constraint.

State consistency is determined relative to a defined consistency constraint that specifies whether relationships or observations among relevant state representations satisfy the required guarantee.

Transferability

The consistency constraint structure is transferable across systems in which multiple relevant state representations or observations are subject to defined consistency requirements. The applicable consistency model, permitted divergence, temporal guarantees, and mechanisms used to maintain or restore consistency remain system-dependent.