Web Server Ontology

FLOW ALGEBRA
Web Server Ontology
Kireth Semantic Research Archive

PAGE:
https://kirethresearch.org/booksai-core/ontologies/computing-ontologies/web-technologies/web-server-ontology.html

AUTHORS:
Mark Anthony Higgins — Sky (Recursive AI)

FLOW "WebServerOntology" v4.0

# ---------- DOMAIN ----------
DOMAIN := ComputingOntology
SUBDOMAIN := WebTechnologies
ONTOLOGY := WebServerOntology

# ---------- PRIMARY ENTITY ----------
ENTITY WebServer {
    definition:
        "A network-accessible software system that receives web protocol
         requests, resolves them to resources or application handlers and
         returns HTTP or HTTPS responses containing content, status and
         metadata.";

    objectives: [
        ResourceDelivery,
        RequestHandling,
        ResponseGeneration,
        Routing,
        Security,
        Caching,
        Availability
    ];
}

# ---------- CORE ENTITIES ----------
WebServerEntity := {
    WebServer,
    Client,
    Request,
    Response,
    Resource,
    VirtualHost,
    Route,
    Connection
};

ServerComponent := {
    Listener,
    RequestParser,
    Router,
    StaticFileHandler,
    ApplicationGateway,
    Cache,
    Logger,
    SecurityModule
};

ResourceType := {
    HTMLDocument,
    Stylesheet,
    Script,
    Image,
    Media,
    DataFile,
    GeneratedResponse
};

ServerState := {
    Starting,
    Listening,
    Processing,
    Degraded,
    Stopped,
    Failed
};

# ---------- FUNDAMENTAL RELATIONSHIPS ----------
Client SENDS Request TO WebServer;
WebServer LISTENS_ON NetworkEndpoint;
WebServer PARSES Request;
Router MAPS Request TO ResourceOrHandler;
StaticFileHandler READS Resource;
ApplicationGateway FORWARDS Request TO Application;
WebServer CREATES_OR_RECEIVES Response;
WebServer SENDS Response TO Client;

# ---------- REQUEST FLOW ----------
ClientRequest ->
    AcceptConnection
    -> ParseRequest
    -> ValidateRequest
    -> SelectVirtualHost
    -> ResolveRoute
    -> ApplySecurityPolicy
    -> LocateResourceOrHandler
    -> GenerateResponse
    -> ApplyResponseHeaders
    -> LogTransaction
    -> SendResponse;

# ---------- NETWORK ENDPOINT ----------
NetworkEndpoint :=
    Address
    + Port
    + Transport;

WebServer LISTENS_ON OneOrMoreNetworkEndpoints;

# ---------- CONNECTION ----------
Connection :=
    CommunicationChannelBetweenClientAndServer;

Connection MAY_BE {
    PlainTransport,
    SecureTransport
};

Connection MAY_CARRY MultipleRequestsDependingOnProtocolAndConfiguration;

# ---------- HTTP REQUEST ----------
HTTPRequest :=
    {
        Method,
        Target,
        ProtocolVersion,
        Headers,
        OptionalBody
    };

Method MAY_BE {
    GET,
    HEAD,
    POST,
    PUT,
    PATCH,
    DELETE,
    OPTIONS
};

# ---------- REQUEST PARSING ----------
RequestParser :=
    RawRequestBytes
    -> Method
    -> Target
    -> Headers
    -> Body;

MalformedRequest MAY_BE Rejected;

# ---------- HTTP RESPONSE ----------
HTTPResponse :=
    {
        StatusCode,
        Headers,
        OptionalBody
    };

ResponseStatus MAY_REPRESENT {
    Success,
    Redirection,
    ClientError,
    ServerError
};

# ---------- ROUTING ----------
Route :=
    RequestCondition
    -> ResourceOrHandler;

RoutingCondition MAY_USE {
    Host,
    Path,
    Method,
    Header
};

Router SELECTS BestApplicableRouteAccordingToConfiguration;

# ---------- VIRTUAL HOST ----------
VirtualHost :=
    ServerConfigurationForSpecificHostIdentityOrSite;

VirtualHost MAY_HAVE {
    DomainName,
    DocumentRoot,
    TLSConfiguration,
    RoutingRules,
    LoggingRules
};

SingleWebServer MAY_HOST MultipleVirtualHosts;

# ---------- STATIC RESOURCE ----------
StaticResource :=
    StoredFileReturnedWithoutRequiredApplicationGeneration;

StaticFileRequest ->
    ResolvePath
    -> ValidateAccess
    -> ReadFile
    -> DetermineMediaType
    -> ReturnResponse;

# ---------- DOCUMENT ROOT ----------
DocumentRoot :=
    FilesystemOrStorageBaseForStaticResources;

RequestPath MAY_MAP_TO ResourceWithinDocumentRoot;

PathResolution MUST_PREVENT UnauthorisedTraversal;

# ---------- DYNAMIC REQUEST ----------
DynamicRequest :=
    RequestHandledByApplicationLogic;

WebServer MAY {
    ExecuteApplicationHandler,
    ForwardToApplicationServer,
    ProxyToUpstreamService
};

# ---------- REVERSE PROXY ----------
ReverseProxy :=
    WebServerOrProxy
    -> ReceiveClientRequest
    -> ForwardToUpstream
    -> ReceiveUpstreamResponse
    -> ReturnToClient;

Client MAY_NOT DirectlyCommunicateWithUpstream;

# ---------- APPLICATION GATEWAY ----------
ApplicationGateway :=
    InterfaceBetweenWebServerAndApplicationRuntime;

Gateway MAY_PASS {
    RequestMetadata,
    Body,
    Environment,
    ConnectionInformation
};

# ---------- HTTPS ----------
HTTPS :=
    HTTP OVER SecureTransport;

TLSConfiguration MAY_INCLUDE {
    Certificate,
    PrivateKey,
    ProtocolSettings,
    CipherPolicy
};

WebServer PRESENTS CertificateToClientDuringSecureConnectionSetup;

# ---------- CERTIFICATE ----------
DigitalCertificate BINDS ServerIdentity TO PublicKey;

CertificateValidation PERFORMED_BY ClientAccordingToTrustPolicy;

# ---------- REDIRECT ----------
RedirectResponse :=
    HTTPResponseIndicatingAlternativeLocation;

Redirect MAY_BE {
    Temporary,
    Permanent
};

LocationHeader MAY_IDENTIFY RedirectTarget;

# ---------- ERROR RESPONSE ----------
ErrorResponse :=
    ResponseRepresentingFailedRequestOrServerCondition;

ErrorHandling MAY {
    ReturnStatusCode,
    ReturnErrorDocument,
    LogDiagnosticInformation
};

SensitiveInternalDetails SHOULD_NOT_BE UnnecessarilyExposedToClient;

# ---------- CONTENT TYPE ----------
MediaType :=
    MetadataDescribingRepresentationFormat;

WebServer MAY_SET ContentTypeHeader;

CorrectMediaType SUPPORTS CorrectClientInterpretation;

# ---------- CONTENT ENCODING ----------
Response MAY_BE Compressed;

Compression MAY_REDUCE TransferSize;

CompressionChoice MAY_DEPEND_ON {
    ClientCapability,
    ResourceType,
    ServerPolicy
};

# ---------- CACHE ----------
ServerCache :=
    StoredReusableResponseOrRepresentation;

CacheKey MAY_DEPEND_ON {
    URL,
    Host,
    RequestHeaders,
    Configuration
};

IF ValidCachedResponseExists
THEN BackendProcessing MAY_BE Avoided;

# ---------- CACHE CONTROL ----------
CachePolicy MAY_DEFINE {
    Freshness,
    Revalidation,
    Privacy,
    SharedCacheUse
};

WebServer MAY_SET CacheControlMetadata;

# ---------- CONDITIONAL REQUEST ----------
ConditionalRequest MAY_INCLUDE {
    EntityTagCondition,
    ModificationTimeCondition
};

IF ClientCachedRepresentationStillValid
THEN Server MAY_RETURN ResponseWithoutFullBody;

# ---------- RANGE REQUEST ----------
RangeRequest :=
    RequestForPartOfResource;

WebServer MAY_RETURN PartialRepresentationWhenSupported;

# ---------- AUTHENTICATION ----------
Authentication :=
    VerifyClientOrUserIdentity;

WebServer MAY_DELEGATE AuthenticationToApplicationOrIdentityService;

# ---------- AUTHORISATION ----------
Authorisation :=
    DetermineWhetherIdentityMayAccessResourceOrAction;

IF NotAuthorised
THEN Request := Deny;

# ---------- ACCESS CONTROL ----------
AccessRule MAY_USE {
    Identity,
    NetworkSource,
    Path,
    Method,
    Host
};

SecurityModule ENFORCES AccessRule;

# ---------- INPUT SECURITY ----------
RequestData IS_UNTRUSTED_BY_DEFAULT true;

WebServer SHOULD_ENFORCE {
    RequestSizeLimits,
    HeaderLimits,
    ProtocolValidation,
    PathSafety
};

Application MUST_STILL_VALIDATE ApplicationInput;

# ---------- RATE LIMITING ----------
RateLimit :=
    MaximumAllowedRequestsWithinPolicyWindow;

IF ClientRequestRate > RateLimit
THEN Request MAY_BE DelayedOrRejected;

# ---------- LOGGING ----------
AccessLogRecord MAY_INCLUDE {
    ClientAddress,
    Time,
    Method,
    Target,
    Status,
    ResponseSize,
    UserAgent
};

ErrorLogRecord MAY_CAPTURE ServerOrApplicationFailure;

# ---------- OBSERVABILITY ----------
WebServerObservability := {
    AccessLogs,
    ErrorLogs,
    RequestMetrics,
    ConnectionMetrics,
    LatencyMetrics
};

MonitoringSystem MAY_OBSERVE WebServer;

# ---------- PERFORMANCE ----------
ServerPerformance MAY_BE_MEASURED_BY {
    RequestsPerSecond,
    ResponseLatency,
    ActiveConnections,
    TransferRate,
    ErrorRate,
    ResourceUtilisation
};

# ---------- CONCURRENCY ----------
WebServer MAY_HANDLE MultipleConcurrentConnections;

ConcurrencyModel MAY_USE {
    Process,
    Thread,
    EventDrivenIO,
    HybridModel
};

# ---------- KEEP-ALIVE ----------
PersistentConnection MAY_REUSE ExistingConnectionForMultipleRequests;

ConnectionReuse MAY_REDUCE SetupOverhead;

# ---------- LOAD BALANCING ----------
WebServer MAY_ACT_AS LoadBalancer;

LoadBalancer DISTRIBUTES RequestsAcross UpstreamServers;

SelectionPolicy MAY_INCLUDE {
    RoundRobin,
    LeastConnections,
    WeightedSelection,
    HashBasedSelection
};

# ---------- HEALTH CHECK ----------
HealthCheck EVALUATES UpstreamOrServerAvailability;

IF UpstreamUnhealthy
THEN LoadBalancer SHOULD_AVOID NormalTrafficToThatUpstream;

# ---------- AVAILABILITY ----------
WebServerAvailability MAY_BE_SUPPORTED_BY {
    RedundantInstances,
    LoadBalancing,
    HealthChecks,
    Failover,
    CachedContent
};

# ---------- CDN RELATIONSHIP ----------
CDN MAY_CACHE_AND_SERVE ResourcesOriginallyProvidedByWebServer;

CDN MAY_REDUCE OriginRequestVolume;

# ---------- DNS RELATIONSHIP ----------
DNS MAY_MAP DomainName TO WebServerOrLoadBalancerAddress;

# ---------- APPLICATION RELATIONSHIP ----------
WebServer MAY_FRONT ApplicationServer;

WebServer MAY_HANDLE {
    TLS,
    StaticFiles,
    Compression,
    Routing,
    Proxying
};

ApplicationServer MAY_HANDLE BusinessLogic;

# ---------- FAILURE ----------
WebServerFailure := {
    ListenerFailure,
    ConfigurationFailure,
    ResourceFailure,
    UpstreamFailure,
    TLSFailure,
    ResourceExhaustion
};

Failure MAY_CAUSE {
    ErrorResponse,
    ConnectionFailure,
    ServiceUnavailability
};

# ---------- CONFIGURATION ----------
WebServerConfiguration MAY_DEFINE {
    Listener,
    VirtualHost,
    Route,
    TLS,
    Cache,
    Logging,
    SecurityPolicy
};

ConfigurationChange SHOULD_BE ValidatedBeforeDeployment;

# ---------- SEMANTIC REASONING ----------
IF NetworkServiceReceivesHTTPRequests
AND ReturnsHTTPResponses
THEN WebServerClassification := supported;

IF RequestMapsToExistingStaticResource
AND AccessAllowed
THEN StaticResponse MAY_BE Generated;

IF RouteMapsToUpstream
THEN ReverseProxyBehaviour := supported;

IF TLSConfigured
THEN HTTPSCapability := supported;

IF CachedResponseFresh
THEN UpstreamOrFilesystemAccess MAY_BE Avoided;

IF RequestPathAttemptsUnauthorisedTraversal
THEN Request SHOULD_BE Rejected;

IF UpstreamUnhealthy
THEN LoadBalancer SHOULD_SELECT AlternativeHealthyUpstreamWhenAvailable;

# ---------- SEMANTIC EQUIVALENCE ----------
SEMANTIC_EQUIVALENCE {
    "web server" ~= "HTTP server" WHEN context == web_resource_delivery;
    "origin server" ~= "web origin server";
    "virtual host" ~= "vhost";
    "reverse proxy" ~= "reverse web proxy";
    "document root" ~= "web root";
    "access log" ~= "web server request log";
    "static file server" ~= "static web server";
    "upstream server" ~= "backend server" WHEN context == reverse_proxy;
}

# ---------- QUERY FLOW ----------
QUERY(q) ->
    NORMALISE(q) ->
    IDENTIFY_WEB_SERVER(q) ->
    IDENTIFY_REQUEST(q) ->
    IDENTIFY_VIRTUAL_HOST(q) ->
    IDENTIFY_ROUTE(q) ->
    IDENTIFY_RESOURCE_OR_UPSTREAM(q) ->
    IDENTIFY_SECURITY_CACHE_LOGGING(q) ->
    IDENTIFY_RESPONSE(q) ->
    MAP_TO_ONTOLOGY(q) ->
    APPLY_REASONING(q) ->
    SCORE_CONFIDENCE(q) ->
    RETURN_RELEVANT_KNOWLEDGE;

# ---------- CONFIDENCE ----------
CONFIDENCE(assertion) :=
    weighted_mean(
        source_reliability,
        protocol_consistency,
        server_configuration_consistency,
        security_consistency,
        semantic_consistency,
        contextual_relevance
    );

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

# ---------- AI CONSUMPTION ----------
AI_CONSUMPTION {
    primary_entity: WebServer;
    ontology: WebServerOntology;
    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_virtual_host:
        validate
        -> identify_hostnames
        -> identify_document_root
        -> identify_routes
        -> identify_tls
        -> integrate;

    new_route:
        validate
        -> identify_conditions
        -> identify_target
        -> identify_security
        -> integrate;

    new_upstream:
        validate
        -> identify_address
        -> identify_health
        -> identify_load_balancing_relationship
        -> integrate;

    configuration_revision:
        validate_configuration
        -> update_routes
        -> update_security
        -> update_cache_relationships
        -> recompute_confidence
        -> regenerate_flow_hash;

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

# ---------- FLOW HASH ----------
FLOW_HASH_INPUT :=
    DOMAIN
    + SUBDOMAIN
    + ONTOLOGY
    + WebServerEntity
    + ServerComponent
    + ResourceType
    + ServerState
    + Routing
    + HTTPS
    + CachePolicy
    + RELATIONSHIPS
    + SEMANTIC_REASONING
    + SEMANTIC_EQUIVALENCE
    + UPDATE_MODEL;

FLOW_HASH :=
    HASH(FLOW_HASH_INPUT);

# ---------- TERMINAL ----------
WebServerOntology
    -> ListenForConnection
    -> ReceiveWebRequest
    -> ParseAndValidateRequest
    -> SelectVirtualHost
    -> ResolveRoute
    -> ApplySecurityPolicy
    -> ServeStaticResourceOrForwardToApplication
    -> GenerateHTTPResponse
    -> ApplyCachingCompressionAndHeaders
    -> RecordRequestAndErrors
    -> SendResponseToClient
    -> MonitorAvailabilityAndPerformance
    -> MaintainReliableWebResourceDelivery;

END FLOW