Realm
Operational Concerns
Correctness, delivery, persistence, recovery, consistency, coordination, and reliability.
Entries
ACID
ACID is a transaction contract: atomicity, consistency, isolation, and durability.
Acknowledgments
Acknowledgments answer: what does a participant or substrate claim has happened?
Arbitration
Arbitration resolves local contention among competing eligible occurrences when the system must select, admit, order, or grant one or more of them.
CAP Theorem
The CAP theorem describes an impossibility for distributed shared data under network partition: a system cannot simultaneously guarantee linearizable consistency, availability, and partition tolerance for all executions.
Commit Boundaries
Commit Boundaries answer: what becomes accepted as one unit, and within which boundary?
Concurrency Control
Concurrency Control answers: How can multiple concurrent histories be reconciled into a single valid history?
Consensus
Consensus answers: how do multiple observers agree on one value despite concurrency, delay, partial failure, or independent local views?
Consistency Models
Consistency Models constrain which observations are valid for a set of events, transitions, versions, sessions, replicas, and ordering relations.
Consistent Cuts
A consistent cut is a selected set of events, versions, observations, or process positions that is closed under the declared causal prerequisites.
Coordination
Coordination answers: how is multi-step or multi-participant work made coherent across observers?
CRDTs
CRDTs, conflict-free replicated data types, are replicated data types designed so that independently updated replicas converge without requiring synchronous coordination for every update.
Delivery Semantics
Delivery Semantics answers: what guarantees does an interaction edge provide?
Distributed Failure Scenarios
Distributed failure scenarios are recurring hazard shapes that appear when effects, observations, commit boundaries, durability, isolation, coordination, and recovery cross independently governed boundaries.
Dual-Write Problem
The dual-write problem is the failure mode that appears when one operation tries to commit two or more effects across independent commit boundaries without one atomic commit protocol or durable recovery protocol connecting them.
Durability
Durability answers: which facts, histories, effects, decisions, or execution material survive which failures?
Fairness
Fairness constrains complete executions so that eligible participants, messages, or actions are not postponed forever under the stated assumptions.
Idempotency
Idempotency is the property that repeated handling of the same semantic input does not produce duplicate domain effects.
Interaction
Interaction answers: how do observers address, observe, notify, or invoke one another?
Isolation
Isolation describes what concurrent operations are allowed to observe of one another while they execute.
Linearization Points
A linearization point is the logical instant at which an operation takes effect in the abstract sequential history used to justify linearizability. It must lie between that operation's invocation and response.
Ordering
Ordering defines the scope within which events, commands, observations, or effects are sequenced.
Persistence
Persistence answers: what is recorded as authoritative material?
Progress Conditions
Progress Conditions classify liveness guarantees for concurrent or distributed operations.
Rate Limiting
Rate Limiting constrains how quickly work may be accepted, dispatched, delivered, or processed.
Reconstitution
Reconstitution answers: how is usable state recovered?
Recovery
Recovery defines how a system returns to coherent operation after failure, interruption, conflict, timeout, overload, or partial progress.
Retry
Retry is the controlled repetition of an operation after a transient failure, timeout, conflict, or unavailable dependency.
Safety and Liveness
Safety and Liveness separate two kinds of operational property of a distributed system.
Scheduling
Scheduling determines which enabled work receives execution opportunity, in what order, on which resources, and under which priority, fairness, deadline, locality, and capacity rules.
Two-Phase Commit
Two-Phase Commit is a coordination protocol for atomic commit across multiple participants.
Version Histories
Version Histories describe the shape of state evolution for a subject, entity, document, repository, projection, or replicated object.