| name | 0.3.6-understand-dps_006 |
| description | [0.3.6] data_duplication is the consequence of database_per_service where the same logical entity may be materialized |
understand-dps_006
CALL NUMBER: deep_microservices_archit.dps_006 : software_architecture_patterns_and_styles(15), deep_event_driven_archite(9)
DEFINITION: data_duplication is the consequence of database_per_service where the same logical entity may be materialized in multiple service databases, kept synchronized through application-level events.
Invoke this skill to understand dps_006 down to its primitives. The RELATIVE ROOT below is the least-fixed-point closure of everything it bundles from — the full import cone, grouped by the lib each prim comes from. Projected from a prover-typed KB (MAP/SWI-Prolog consistency gate): every reference below resolves.
THE RELATIVE ROOT (the import cone, by lib)
from ?
- distributed_transaction (d3): A transaction that spans multiple independent services or database_per_service instances, requiring coordination to maintain atomicity across nodes where each participant may reside in a different process or machine.
from deep_event_driven_archite
- pubsub_broker (d3): The intermediary component that receives messages from publishers and forwards them to subscribers based on topic subscriptions; may also perform filtering.
- pubsub_topic (d3): A named channel or subject through which messages are routed from publishers to interested subscribers; the publisher has no knowledge of subscriber identities or count.
- pubsub_message (d3): The payload broadcast by a publisher on a topic; in pub/sub it is typically ephemeral and not persisted beyond active subscriber consumption.
- pubsub_dead_letter (d4): A destination for messages that cannot be successfully delivered to any subscriber, capturing failures for later inspection or replay.
- pubsub_subscription (d4): An active registration linking a subscriber to a topic; may be durable (surviving subscriber disconnection) or transient (active only while subscriber is connected).
- pubsub_topic_namespace (d4): A hierarchical or scoped naming scheme for topics (e.g., orders.new, orders.cancelled) that enables subscribers to express interest at varying levels of granularity.
- pubsub_content_filter (d4): A predicate or attribute-based rule applied at the broker or subscriber side to select a subset of messages on a topic for delivery.
- pubsub_message_schema (d4): A structured format (JSON, Avro, Protobuf) defining the shape of messages on a topic, enabling subscribers to deserialize and interpret published events.
- pubsub_subscriber (d5): An entity that expresses interest in one or more topics and receives messages published to those topics; receives only messages matching its subscriptions.
from deep_microservices_archit
- dps_007 (d1): api_composition is the pattern where a client or gateway aggregates data from multiple service databases by querying each service's API and combining results, compensating for the lack of cross-service SQL joins.
- dps_014 (d1): eventual_consistency_model is the consistency guarantee that results from database_per_service: writes are immediately durable in one service's database, and other services receive updates asynchronously via event_streaming or message_queue.
- gateway_routing__integration (d4): Integration with load_balancing to distribute requests across multiple instances of a backend service.
- gateway_routing_backend_service (d4): A microservice or backend resource that receives forwarded requests from the gateway.
- gateway_routing_circuit_breaker_integration (d4): Integration with circuit_breaker logic to prevent routing to failing backend services.
- gateway_routing_fallback_route (d4): A predefined route or behavior triggered when primary routing fails or no route matches.
- gateway_routing_response_aggregation (d4): The combination of responses from multiple backend services into a single client response.
- gateway_routing_reverse_proxy (d4): The mechanism that forwards matched requests to backend services and returns responses to clients.
- gateway_routing_route (d4): A defined mapping between incoming request criteria and a target backend service endpoint.
- gateway_routing_service_discovery_integration (d4): Integration with service_discovery to dynamically resolve backend service network locations.
- gateway_routing_header_transformation (d5): The addition, removal, or modification of HTTP headers during request forwarding.
- gateway_routing_path_rewrite (d5): A transformation that modifies the request path before forwarding to the backend service.
- gateway_routing_route_definition (d5): The declarative or imperative specification of a route including matching criteria and target service.
- gateway_routing_request_matcher (d6): A component that evaluates incoming requests against route matching criteria.
- gateway_routing_route_priority (d6): The ordering rule that determines which route takes precedence when multiple routes match.
- gateway_routing_header_condition (d7): A matching rule based on request or response header values for routing decisions.
- gateway_routing_http_method_filter (d7): A routing constraint based on HTTP method (GET, POST, PUT, DELETE) for route matching.
from software_architecture_patterns_and_styles
- api_gateway (d2): A server entry point that routes requests to backend services, handling cross-cutting concerns like authentication, rate_limiting, and protocol_translation.
- event_streaming (d2): A data handling approach where events are captured in order as an immutable log (stream), allowing multiple consumers to read independently (e.g., Kafka, Pulsar).
- message_queue (d2): A communication mechanism where messages are placed in a queue by producers and consumed asynchronously by consumers, decoupling sender and receiver in time and space.
- publish_subscribe_pattern (d2): A messaging pattern where publishers send messages to a topic without knowing subscribers, and subscribers receive messages published to topics they are interested in.
- saga_pattern (d2): A pattern for managing distributed transactions across microservices using a sequence of local transactions with compensating actions for rollback, replacing distributed transactions.
- gateway_routing (d3): A pattern where an API_gateway routes requests to appropriate backend services based on request characteristics (URL path, headers) without the client knowing service locations.
- rate_limiting (d3): A traffic_management technique that controls how many requests a client can make in a given time period, protecting services from overload and abuse.
- choreography_pattern (d3): A distributed coordination pattern where services exchange events without a central orchestrator; each service knows what to do based on received events.
- orchestration_pattern (d3): A distributed coordination pattern where a central coordinator (orchestrator) directs the flow of operations across services, contrasting with choreography.
- event_driven_architecture (d4): A software design pattern where the flow of the program is determined by events (user actions, sensor outputs, messages) and the propagation of events through the system.
- service_oriented_architecture (d4): An architectural pattern where application components provide services to other components via a communication protocol, typically over a network. SOA emphasizes interoperability and composition of services.
- load_balancing (d5): A technique for distributing network traffic or workload across multiple servers to ensure no single resource is overwhelmed, improving responsiveness and availability.
- service_discovery (d5): The automatic detection of services and their network locations (IP address, port) in a dynamic infrastructure, typically via client_side_discovery or server_side_discovery.
- (d6): Scaling out by adding more machines to a system, as opposed to vertical_scaling which adds resources to existing machines.
CONSUMERS (what needs this)
dps_001
Projected from the software architecture patterns and styles KB (211 concepts / 192 relations) — consistency-typed by MAP; the facet list after the colon IS the cross-lib dependency web.
(leaf — this is an actual skill.)
