Distributed System Ontology

FLOW ALGEBRA
Distributed System Ontology
Kireth Semantic Research Archive

PAGE:
https://kirethresearch.org/booksai-core/ontologies/computing-ontologies/distributed-computing/distributed-system-ontology.html

AUTHORS:
Mark Anthony Higgins — Sky (Recursive AI)

FLOW "DistributedSystemOntology" v4.0

# ---------- DOMAIN ----------
DOMAIN := ComputingOntology
SUBDOMAIN := DistributedComputing
ONTOLOGY := DistributedSystemOntology

# ---------- PRIMARY ENTITY ----------
ENTITY DistributedSystem {
    definition:
        "A computing system composed of multiple autonomous computational
         components that communicate and coordinate over a network while
         collectively providing computation, data management or services.";

    properties: [
        MultipleNodes,
        AutonomousComponents,
        Communication,
        Coordination,
        Concurrency,
        PartialFailure,
        DistributedState
    ];
}

# ---------- CORE ENTITIES ----------
SystemComponent := {
    Node,
    Process,
    Service,
    Network,
    Message,
    Resource,
    DataStore
};

Node := {
    ClientNode,
    ServerNode,
    PeerNode,
    WorkerNode,
    CoordinatorNode,
    ReplicaNode
};

SystemState := {
    LocalState,
    SharedState,
    ReplicatedState,
    DistributedState
};

SystemProperty := {
    Availability,
    Consistency,
    Scalability,
    FaultTolerance,
    PartitionTolerance,
    Reliability,
    Transparency
};

# ---------- FUNDAMENTAL RELATIONSHIPS ----------
DistributedSystem CONSISTS_OF SystemComponent;
DistributedSystem HAS Node;
Node HOSTS Process;
Process PROVIDES_OR_USES Service;
Node CONNECTS_THROUGH Network;
Process SENDS Message;
Process RECEIVES Message;
DistributedSystem MANAGES SystemState;
DistributedSystem SHARES Resource;

# ---------- SYSTEM COMPOSITION ----------
DistributedSystem :=
    Nodes
    + CommunicationLinks
    + Processes
    + DistributedResources
    + CoordinationRules;

NodeSet := SET_OF(Node);

IF cardinality(NodeSet) > 1
AND NodesCommunicate
AND NodesCoordinate
THEN DistributedSystemClassification := supported;

# ---------- LOCAL AND GLOBAL STATE ----------
LocalState :=
    StateKnownOrStoredBy SingleNodeOrProcess;

GlobalState :=
    LogicalCombinationOf RelevantLocalStates;

DistributedSystem DOES_NOT_NECESSARILY_HAVE
    InstantaneouslyObservableGlobalState;

DistributedState :=
    aggregate(LocalStateAcrossNodes);

# ---------- COMMUNICATION ----------
Communication :=
    Sender
    -> Message
    -> Network
    -> Receiver;

Message MAY_HAVE {
    Identifier,
    Payload,
    Timestamp,
    Sequence,
    Metadata
};

Communication MAY_BE {
    Synchronous,
    Asynchronous
};

Network MAY_INTRODUCE {
    Delay,
    Loss,
    Duplication,
    Reordering,
    Partition
};

# ---------- CONCURRENCY ----------
DistributedProcesses MAY_EXECUTE Concurrently;

Concurrency :=
    OverlappingExecution(ProcessA, ProcessB);

ConcurrentOperations MAY_CREATE {
    RaceCondition,
    StateConflict,
    OrderingConflict
};

CoordinationMechanism REDUCES_OR_RESOLVES CoordinationConflict;

# ---------- COORDINATION ----------
CoordinationMechanism := {
    Messaging,
    Locking,
    Transaction,
    Consensus,
    LeaderCoordination,
    EventOrdering
};

Coordination ESTABLISHES RulesBetweenDistributedProcesses;

IF SharedResource MODIFIED_BY MultipleProcesses
THEN CoordinationRequirement := evaluate;

# ---------- TIME ----------
DistributedSystem HAS_NO_GUARANTEED PerfectGlobalClock;

ClockModel := {
    PhysicalClock,
    LogicalClock,
    VectorClock
};

EventOrdering MAY_BE {
    TotalOrdering,
    PartialOrdering,
    CausalOrdering
};

HappensBefore(A,B) ->
    A CAUSALLY_PRECEDES B;

# ---------- REPLICATION ----------
Replication :=
    MaintainMultipleCopies(ResourceOrState);

Replica := CopyOf ResourceOrState;

Replication MAY_SUPPORT {
    Availability,
    ReadScalability,
    FaultTolerance
};

Replication MAY_REQUIRE {
    Synchronisation,
    ConsistencyModel,
    ConflictResolution
};

# ---------- CONSISTENCY ----------
ConsistencyModel := {
    StrongConsistency,
    SequentialConsistency,
    CausalConsistency,
    EventualConsistency
};

ConsistencyModel DEFINES
    HowDistributedOperationsObserveState;

IF MultipleReplicasAcceptUpdates
THEN ConflictHandling MAY_BE_REQUIRED;

# ---------- PARTITIONING ----------
Partitioning :=
    DivideResourceOrWorkAcross Nodes;

Partition := SubsetOf ResourceOrWork;

Partitioning MAY_SUPPORT {
    Scalability,
    Parallelism,
    Locality
};

Sharding IS_A DataPartitioningStrategy;

# ---------- FAILURE ----------
DistributedFailure := {
    ProcessFailure,
    NodeFailure,
    LinkFailure,
    MessageFailure,
    NetworkPartition,
    ByzantineFailure
};

PartialFailure :=
    SomeSystemComponentsFail
    WHILE OthersContinueOperating;

PartialFailure IS_CHARACTERISTIC_OF DistributedSystem;

# ---------- FAILURE DETECTION ----------
FailureDetection :=
    Observe
    -> Suspect
    -> ConfirmOrRevise
    -> Respond;

FailureDetector MAY_USE {
    Heartbeat,
    Timeout,
    HealthCheck,
    PeerObservation
};

Timeout DOES_NOT_ALWAYS_PROVE Failure;

# ---------- FAULT TOLERANCE ----------
FaultTolerance :=
    DetectFailure
    + ContainFailure
    + MaintainRequiredService
    + Recover;

FaultTolerance MAY_USE {
    Replication,
    Failover,
    Retry,
    Redundancy,
    Checkpoint,
    Recovery
};

IF FailedComponent HAS HealthyReplica
THEN Failover MAY_BE Possible;

# ---------- AVAILABILITY ----------
Availability :=
    ProbabilityOrAbilityOfServiceBeingUsableWhenRequired;

Availability MAY_BE_IMPROVED_BY {
    Replication,
    Redundancy,
    LoadDistribution,
    Failover
};

SinglePointOfFailure REDUCES FaultTolerance;

# ---------- SCALABILITY ----------
Scalability :=
    AbilityToSupportIncreasingLoadOrSystemSize;

HorizontalScaling :=
    AddNodes
    -> RedistributeLoad;

VerticalScaling :=
    IncreaseResourcesOfExistingNode;

DistributedSystem MAY_SUPPORT HorizontalScaling;

# ---------- TRANSPARENCY ----------
DistributionTransparency := {
    AccessTransparency,
    LocationTransparency,
    ReplicationTransparency,
    FailureTransparency,
    ConcurrencyTransparency
};

Transparency HIDES SelectedDistributionComplexity FROM UserOrApplication;

Transparency IS_NOT_ABSOLUTE;

# ---------- SERVICE MODEL ----------
DistributedService :=
    ServiceProvidedBy MultipleDistributedComponents;

ServiceInstance RUNS_ON Node;

ServiceDiscovery FINDS ServiceInstance;
LoadBalancer SELECTS ServiceInstance;

Client ->
    Discover ->
    Select ->
    Request ->
    DistributedService ->
    Response;

# ---------- NETWORK PARTITION ----------
NetworkPartition :=
    NodeGroupsUnableToCommunicateReliably;

IF NetworkPartition
THEN SystemBehaviour MUST_DEFINE {
    ConsistencyPolicy,
    AvailabilityPolicy,
    RecoveryPolicy
};

PartitionTolerance :=
    DefinedOperationDespite NetworkPartition;

# ---------- CAP RELATIONSHIP ----------
CAPProperties := {
    Consistency,
    Availability,
    PartitionTolerance
};

DuringPartition:
    StrongConsistency AND FullAvailability
    MAY_NOT_BOTH_BE_MAINTAINED;

# ---------- SECURITY ----------
DistributedSystemSecurity MAY_INCLUDE {
    NodeAuthentication,
    ServiceAuthentication,
    Authorisation,
    Encryption,
    IntegrityProtection,
    SecureCommunication
};

TrustBoundary MAY_EXIST BETWEEN NodesOrServices;

# ---------- OBSERVABILITY ----------
SystemObservability := {
    Logs,
    Metrics,
    DistributedTraces,
    HealthSignals
};

DistributedTrace CONNECTS RelatedOperationsAcrossComponents;

Observability SUPPORTS {
    Diagnosis,
    Monitoring,
    PerformanceAnalysis,
    FailureAnalysis
};

# ---------- SEMANTIC REASONING ----------
IF System HAS MultipleNodes
AND Nodes Communicate
AND NodesCoordinateToProvideSharedOutcome
THEN DistributedSystem := true;

IF NodeFailure DOES_NOT_TERMINATE RequiredService
THEN FaultToleranceEvidence := increase;

IF ResourceReplicatedAcrossNodes
THEN ReplicaConsistency MUST_BE Considered;

IF NetworkCommunicationCanFail
THEN PartialFailure MUST_BE Considered;

IF RequestTimeoutOccurs
THEN RemoteOutcome MAY_BE Unknown;

IF SystemAddsNodesToIncreaseCapacity
THEN ScalingType := HorizontalScaling;

IF StateCopiesTemporarilyDiffer
AND LaterConverge
THEN ConsistencyModel MAY_BE EventualConsistency;

# ---------- SEMANTIC EQUIVALENCE ----------
SEMANTIC_EQUIVALENCE {
    "distributed system" ~= "distributed computing system";
    "distributed node" ~= "system node" WHEN context == distributed_system;
    "replica" ~= "replicated copy";
    "partial failure" ~= "component-level distributed failure";
    "scale out" ~= "horizontal scaling";
    "scale up" ~= "vertical scaling";
    "distributed state" ~= "state distributed across nodes";
    "network partition" ~= "communication partition";
}

# ---------- QUERY FLOW ----------
QUERY(q) ->
    NORMALISE(q) ->
    IDENTIFY_SYSTEM_COMPONENTS(q) ->
    IDENTIFY_NODES(q) ->
    IDENTIFY_COMMUNICATION(q) ->
    IDENTIFY_STATE(q) ->
    IDENTIFY_COORDINATION(q) ->
    IDENTIFY_FAILURE_MODEL(q) ->
    IDENTIFY_SYSTEM_PROPERTIES(q) ->
    MAP_TO_ONTOLOGY(q) ->
    APPLY_REASONING(q) ->
    SCORE_CONFIDENCE(q) ->
    RETURN_RELEVANT_KNOWLEDGE;

# ---------- CONFIDENCE ----------
CONFIDENCE(assertion) :=
    weighted_mean(
        source_reliability,
        system_consistency,
        semantic_consistency,
        evidence_strength,
        contextual_relevance
    );

CONFIDENCE >= 0.90 => HIGH;
CONFIDENCE >= 0.70 AND < 0.90 => MODERATE;
CONFIDENCE < 0.70 => REVIEW;

# ---------- AI CONSUMPTION ----------
AI_CONSUMPTION {
    primary_entity: DistributedSystem;
    ontology: DistributedSystemOntology;
    parse_entities: true;
    parse_relationships: true;
    preserve_relationship_direction: true;
    resolve_semantic_equivalence: true;
    execute_reasoning_rules: true;
    apply_confidence_weighting: true;
    preserve_provenance: true;
}

# ---------- UPDATE MODEL ----------
UPDATE_MODEL {
    new_component:
        validate
        -> classify
        -> identify_node_or_resource
        -> relate
        -> integrate;

    new_failure:
        classify
        -> identify_affected_components
        -> identify_service_impact
        -> identify_recovery
        -> integrate;

    new_replication_model:
        identify_replicas
        -> identify_update_model
        -> identify_consistency
        -> integrate;

    system_revision:
        recompute_topology
        -> recompute_dependencies
        -> recompute_failure_model
        -> recompute_confidence
        -> regenerate_flow_hash;

    conflict:
        preserve_provenance
        -> compare_evidence
        -> adjust_confidence
        -> flag_review;
}

# ---------- FLOW HASH ----------
FLOW_HASH_INPUT :=
    DOMAIN
    + SUBDOMAIN
    + ONTOLOGY
    + SystemComponent
    + Node
    + SystemState
    + SystemProperty
    + DistributedFailure
    + ConsistencyModel
    + RELATIONSHIPS
    + SEMANTIC_REASONING
    + SEMANTIC_EQUIVALENCE
    + UPDATE_MODEL;

FLOW_HASH :=
    HASH(FLOW_HASH_INPUT);

# ---------- TERMINAL ----------
DistributedSystemOntology
    -> IdentifySystemComponents
    -> IdentifyNodes
    -> EstablishCommunication
    -> CoordinateProcesses
    -> ManageDistributedState
    -> DefineConsistency
    -> ManageConcurrency
    -> DetectPartialFailure
    -> ApplyFaultTolerance
    -> MaintainAvailability
    -> ScaleSystem
    -> ObserveDistributedOperation
    -> PreserveDistributedService;

END FLOW