Microservices Ontology

FLOW ALGEBRA
Microservices Ontology
Kireth Semantic Research Archive

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

AUTHORS:
Mark Anthony Higgins — Sky (Recursive AI)

FLOW "MicroservicesOntology" v4.0

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

# ---------- PRIMARY ENTITY ----------
ENTITY Microservices {
    definition:
        "A distributed software architecture in which an application is
         composed of independently deployable services organised around
         bounded capabilities and communicating through defined interfaces
         or messaging mechanisms.";

    objectives: [
        ServiceAutonomy,
        IndependentDeployment,
        Scalability,
        Modularity,
        FaultIsolation,
        EvolutionaryChange
    ];
}

# ---------- CORE ENTITIES ----------
Microservice := {
    ServiceIdentity,
    ServiceInterface,
    ServiceImplementation,
    ServiceData,
    ServiceConfiguration,
    ServiceInstance
};

ServiceInteraction := {
    SynchronousRequest,
    AsynchronousMessage,
    Event,
    Command,
    Query
};

InfrastructureEntity := {
    ServiceRegistry,
    APIEndpoint,
    Gateway,
    MessageBroker,
    LoadBalancer,
    Orchestrator,
    ObservabilitySystem
};

ServiceState := {
    Starting,
    Healthy,
    Degraded,
    Unavailable,
    Stopped
};

# ---------- FUNDAMENTAL RELATIONSHIPS ----------
Application COMPOSED_OF Microservice;
Microservice IMPLEMENTS BusinessCapability;
Microservice EXPOSES ServiceInterface;
ServiceInstance RUNS Microservice;
Microservice COMMUNICATES_WITH Microservice;
Microservice MAY_OWN ServiceData;
ServiceRegistry DISCOVERS_OR_RECORDS ServiceInstance;
Gateway ROUTES Request TO Microservice;
MessageBroker TRANSPORTS Message;

# ---------- SERVICE BOUNDARY ----------
ServiceBoundary :=
    Encapsulate(
        Capability,
        Implementation,
        DataOwnership,
        Interface
    );

Microservice SHOULD_MINIMISE DirectInternalCoupling;

BoundedCapability MAPS_TO Microservice;

IF TwoServicesRequireSharedInternalState
THEN Coupling := INCREASE;

# ---------- SERVICE INTERFACE ----------
ServiceInterface := {
    API,
    MessageContract,
    EventContract
};

ServiceConsumer USES ServiceInterface;
ServiceProvider IMPLEMENTS ServiceInterface;

InterfaceContract DEFINES {
    RequestOrMessageShape,
    ResponseOrEventShape,
    Semantics,
    Version
};

# ---------- SYNCHRONOUS COMMUNICATION ----------
SynchronousRequest :=
    ClientService
    -> Request
    -> ProviderService
    -> Execute
    -> Response;

Caller MAY_WAIT_FOR Response;

IF ProviderUnavailable
THEN SynchronousRequest MAY_FAIL;

# ---------- ASYNCHRONOUS COMMUNICATION ----------
AsynchronousMessage :=
    Producer
    -> MessageBroker
    -> Consumer;

Producer MAY_CONTINUE_WITHOUT ImmediateConsumerResponse;

AsynchronousCommunication MAY_REDUCE TemporalCoupling;

# ---------- EVENT-DRIVEN INTERACTION ----------
DomainEvent :=
    RecordOfSignificantStateChange;

Service PUBLISHES DomainEvent;
OtherService MAY_SUBSCRIBE_TO DomainEvent;

EventDrivenFlow :=
    StateChange
    -> PublishEvent
    -> DeliverEvent
    -> ConsumerReaction;

# ---------- SERVICE DISCOVERY ----------
ServiceDiscovery :=
    ServiceInstance
    -> Register
    -> ServiceRegistry
    -> Discover
    -> SelectInstance;

DynamicServiceEnvironment MAY_REQUIRE ServiceDiscovery;

# ---------- API GATEWAY ----------
APIGateway :=
    ExternalRequest
    -> Route
    -> Microservice;

APIGateway MAY_PERFORM {
    Routing,
    Authentication,
    RateLimiting,
    RequestTransformation,
    Aggregation
};

# ---------- LOAD BALANCING ----------
LoadBalancer DISTRIBUTES Requests ACROSS ServiceInstance;

IF MultipleHealthyInstances
THEN Request MAY_BE RoutedToAnyEligibleInstance;

LoadBalancing SUPPORTS HorizontalScaling;

# ---------- INDEPENDENT DEPLOYMENT ----------
Microservice MAY_HAVE IndependentDeploymentLifecycle;

Deployment :=
    Build
    -> Test
    -> Package
    -> Release
    -> Deploy
    -> Verify;

IF ServiceInterfaceCompatibilityMaintained
THEN Service MAY_BE UpdatedIndependently;

# ---------- SERVICE VERSIONING ----------
ServiceVersion :=
    VersionOf(MicroserviceOrInterface);

ConsumerCompatibility :=
    f(
        InterfaceVersion,
        ContractCompatibility,
        BehaviourCompatibility
    );

IF BreakingInterfaceChange
THEN ConsumerMigration MAY_BE_REQUIRED;

# ---------- DATA OWNERSHIP ----------
Microservice MAY_OWN DataStore;

ServiceA SHOULD_NOT DirectlyModify ServiceBPrivateData;

CrossServiceDataRequirement MAY_USE {
    API,
    Event,
    ReplicatedReadModel
};

DataOwnership SUPPORTS ServiceAutonomy;

# ---------- DISTRIBUTED TRANSACTION ----------
CrossServiceOperation MAY_SPAN MultipleMicroservices;

DistributedTransactionChallenge :=
    MaintainingBusinessConsistencyAcrossServices;

CoordinationPattern MAY_INCLUDE {
    Saga,
    CompensatingAction,
    EventDrivenCoordination
};

Saga :=
    SequenceOfLocalTransactions
    + CompensatingActions;

# ---------- FAILURE MODEL ----------
MicroserviceFailure := {
    ServiceInstanceFailure,
    DependencyFailure,
    NetworkFailure,
    Timeout,
    MessageFailure,
    DataStoreFailure
};

Failure MAY_BE Partial;

IF DependencyUnavailable
THEN CallingService SHOULD_HANDLE FailureAccordingToPolicy;

# ---------- RESILIENCE ----------
ResiliencePattern := {
    Timeout,
    Retry,
    CircuitBreaker,
    Bulkhead,
    Fallback,
    Replication
};

Retry MAY_RECOVER TransientFailure;

IF RetryUsed
THEN Idempotency SHOULD_BE Considered;

CircuitBreaker MAY_LIMIT RepeatedCallsToFailingDependency;

Bulkhead MAY_LIMIT FailurePropagation;

# ---------- CIRCUIT BREAKER ----------
CircuitState := {
    Closed,
    Open,
    HalfOpen
};

IF FailureThresholdExceeded
THEN CircuitState := Open;

IF RecoveryProbeSucceeds
THEN CircuitState MAY_RETURN_TO Closed;

# ---------- SCALABILITY ----------
Microservice MAY_SCALE Independently;

ScaleOut(Service) ->
    AddServiceInstance
    -> RegisterInstance
    -> DistributeLoad;

IF ServiceDemandHigh
THEN ScaleSpecificService MAY_BE PreferredOverScalingWholeApplication;

# ---------- ORCHESTRATION ----------
ServiceOrchestrator MAY_MANAGE {
    Deployment,
    Scheduling,
    Scaling,
    Health,
    Restart,
    Networking
};

DesiredState ->
    Orchestrator ->
    CompareActualState ->
    Reconcile;

# ---------- OBSERVABILITY ----------
MicroserviceObservability := {
    Logging,
    Metrics,
    DistributedTracing,
    HealthChecks
};

DistributedTrace CONNECTS RequestPathAcrossServices;

CorrelationIdentifier LINKS RelatedServiceEvents;

IF FailureOccursAcrossDependencyChain
THEN DistributedTrace MAY_SUPPORT Diagnosis;

# ---------- SECURITY ----------
MicroserviceSecurity MAY_REQUIRE {
    ServiceAuthentication,
    UserAuthentication,
    Authorisation,
    Encryption,
    SecretManagement,
    NetworkPolicy,
    LeastPrivilege
};

ServiceIdentity IDENTIFIES MicroserviceOrInstance;

IF ServiceNotAuthorised
THEN ServiceRequest := Deny;

# ---------- CONFIGURATION ----------
ServiceConfiguration SHOULD_BE SeparatelyManageableFromCode;

Configuration MAY_INCLUDE {
    Endpoint,
    FeatureSetting,
    ResourceLimit,
    SecuritySetting
};

ConfigurationChange MAY_AFFECT RuntimeBehaviour;

# ---------- HEALTH ----------
HealthCheck EVALUATES ServiceInstance;

IF HealthCheckFails
THEN ServiceInstanceState := Unhealthy;

UnhealthyInstance SHOULD_BE RemovedFromNormalRouting;

# ---------- MICROSERVICES VS MONOLITH ----------
MonolithicApplication :=
    ApplicationDeployedAsSinglePrimaryUnit;

MicroservicesApplication :=
    ApplicationComposedOfIndependentServices;

Microservices MAY_INCREASE {
    DeploymentFlexibility,
    OperationalComplexity,
    NetworkCommunication
};

Microservices != AutomaticallyBetterArchitecture;

# ---------- SEMANTIC REASONING ----------
IF ApplicationComposedOfIndependentDeployableServices
AND ServicesCommunicateThroughDefinedInterfaces
THEN MicroservicesClassification := supported;

IF ServiceOwnsCapabilityAndData
THEN ServiceAutonomyEvidence := increase;

IF ServiceCanScaleWithoutScalingOtherServices
THEN IndependentScalability := true;

IF SynchronousDependencyChainLong
THEN CascadingFailureRisk := increase;

IF RetryOnNonIdempotentOperation
THEN DuplicateSideEffectRisk := increase;

IF ServiceDirectlyReadsAnotherServicePrivateDatabase
THEN ServiceCoupling := increase;

IF MultipleServicesParticipateInBusinessTransaction
THEN DistributedConsistencyStrategy := required;

# ---------- SEMANTIC EQUIVALENCE ----------
SEMANTIC_EQUIVALENCE {
    "microservices" ~= "microservice architecture";
    "microservice" ~= "independently deployable service" WHEN context == architecture;
    "service discovery" ~= "microservice discovery";
    "API gateway" ~= "service gateway" WHEN context == microservices;
    "service registry" ~= "microservice registry";
    "distributed tracing" ~= "cross-service tracing";
    "circuit breaker" ~= "service circuit breaker";
    "saga pattern" ~= "distributed saga";
}

# ---------- QUERY FLOW ----------
QUERY(q) ->
    NORMALISE(q) ->
    IDENTIFY_MICROSERVICES(q) ->
    IDENTIFY_SERVICE_BOUNDARIES(q) ->
    IDENTIFY_INTERFACES(q) ->
    IDENTIFY_COMMUNICATION_MODEL(q) ->
    IDENTIFY_DATA_OWNERSHIP(q) ->
    IDENTIFY_DEPENDENCIES(q) ->
    IDENTIFY_RESILIENCE(q) ->
    MAP_TO_ONTOLOGY(q) ->
    APPLY_REASONING(q) ->
    SCORE_CONFIDENCE(q) ->
    RETURN_RELEVANT_KNOWLEDGE;

# ---------- CONFIDENCE ----------
CONFIDENCE(assertion) :=
    weighted_mean(
        source_reliability,
        architectural_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: Microservices;
    ontology: MicroservicesOntology;
    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_service:
        validate
        -> identify_capability
        -> identify_interface
        -> identify_data_ownership
        -> map_dependencies
        -> integrate;

    new_interface:
        validate
        -> identify_provider
        -> identify_consumers
        -> evaluate_compatibility
        -> integrate;

    new_dependency:
        identify_services
        -> classify_interaction
        -> identify_failure_modes
        -> identify_resilience_controls
        -> integrate;

    deployment_revision:
        update_service_instances
        -> update_versions
        -> update_health
        -> recompute_relationships
        -> regenerate_flow_hash;

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

# ---------- FLOW HASH ----------
FLOW_HASH_INPUT :=
    DOMAIN
    + SUBDOMAIN
    + ONTOLOGY
    + Microservice
    + ServiceInteraction
    + InfrastructureEntity
    + ServiceState
    + ResiliencePattern
    + RELATIONSHIPS
    + SEMANTIC_REASONING
    + SEMANTIC_EQUIVALENCE
    + UPDATE_MODEL;

FLOW_HASH :=
    HASH(FLOW_HASH_INPUT);

# ---------- TERMINAL ----------
MicroservicesOntology
    -> IdentifyBusinessCapabilities
    -> DefineServiceBoundaries
    -> DefineServiceInterfaces
    -> EstablishDataOwnership
    -> DeployIndependentServices
    -> DiscoverServiceInstances
    -> RouteRequestsOrMessages
    -> CoordinateDistributedOperations
    -> ApplyResiliencePatterns
    -> ScaleServicesIndependently
    -> ObserveDistributedExecution
    -> MaintainServiceAutonomy;

END FLOW