vocabulary:
  name: Resilience4j Vocabulary
  description: Domain vocabulary for the Resilience4j fault tolerance library for Java.
  version: "1.0"
  created: "2026-05-02"
  terms:
    - term: CircuitBreaker
      definition: >-
        A resilience pattern that prevents cascading failures by monitoring call
        success/failure rates and opening the circuit (blocking calls) when
        thresholds are exceeded. Implements three states: CLOSED, OPEN, HALF_OPEN.
      states:
        - CLOSED
        - OPEN
        - HALF_OPEN
        - DISABLED
        - FORCED_OPEN
      related: ["faultTolerance", "RateLimiter", "Bulkhead"]

    - term: CircuitBreakerState
      definition: The current operational state of a circuit breaker.
      values:
        - CLOSED: "Normal operation; calls are permitted"
        - OPEN: "Circuit is open; calls are blocked and fail fast"
        - HALF_OPEN: "Limited calls permitted to test if service has recovered"
        - DISABLED: "Circuit breaker is disabled; all calls permitted"
        - FORCED_OPEN: "Circuit is forced open; no calls permitted"
      related: ["CircuitBreaker"]

    - term: SlidingWindow
      definition: >-
        The mechanism used by a circuit breaker to record and analyze call
        outcomes. Can be COUNT_BASED (last N calls) or TIME_BASED (last N seconds).
      values:
        - COUNT_BASED
        - TIME_BASED
      related: ["CircuitBreaker"]

    - term: FailureRateThreshold
      definition: >-
        The percentage of failed calls that triggers the circuit breaker to
        open. Default: 50%. Calculated over the sliding window.
      related: ["CircuitBreaker", "SlidingWindow"]

    - term: SlowCallRateThreshold
      definition: >-
        The percentage of calls exceeding slowCallDurationThreshold that
        triggers the circuit to open. Default: 100%.
      related: ["CircuitBreaker"]

    - term: RateLimiter
      definition: >-
        A resilience pattern that controls the rate of calls to a service,
        allowing a maximum number of calls within a refresh period to prevent
        overloading downstream systems.
      configuration:
        - limitForPeriod
        - limitRefreshPeriod
        - timeoutDuration
      related: ["CircuitBreaker", "Bulkhead"]

    - term: Bulkhead
      definition: >-
        A resilience pattern that limits the number of concurrent calls to a
        service, preventing resource exhaustion. Supports SemaphoreBulkhead
        (concurrent call limit) and ThreadPoolBulkhead.
      types:
        - SemaphoreBulkhead
        - ThreadPoolBulkhead
      related: ["CircuitBreaker", "RateLimiter"]

    - term: Retry
      definition: >-
        A resilience pattern that automatically retries failed calls with
        configurable wait duration, maximum attempts, and backoff strategies
        (fixed, exponential, randomized).
      configuration:
        - maxAttempts
        - waitDuration
        - exponentialBackoffMultiplier
        - retryExceptions
        - ignoreExceptions
      related: ["CircuitBreaker", "TimeLimiter"]

    - term: TimeLimiter
      definition: >-
        A resilience pattern that sets a timeout duration for calls to external
        services. Cancels running futures when the timeout is exceeded.
      configuration:
        - timeoutDuration
        - cancelRunningFuture
      related: ["Retry", "CircuitBreaker"]

    - term: Cache
      definition: >-
        A resilience pattern that stores successful call results in a cache
        to avoid redundant downstream calls. Based on javax.cache (JCache).
      related: ["performance", "resilience"]

    - term: Decorator
      definition: >-
        A higher-order function in Resilience4j that wraps a functional
        interface (Supplier, Function, Runnable, etc.) with resilience behavior.
      related: ["functionalProgramming"]

    - term: FallbackMethod
      definition: >-
        An alternative method called when a resilience4j-protected call fails
        after all retries are exhausted or the circuit is open.
      related: ["Retry", "CircuitBreaker"]

    - term: Event
      definition: >-
        A recorded occurrence in a resilience component's lifecycle
        (e.g., circuit state change, retry attempt, rate limit exceeded).
        Published via event consumer API and Spring Boot Actuator endpoints.
      related: ["CircuitBreaker", "Retry", "monitoring"]

    - term: SpringBootActuator
      definition: >-
        Spring Boot management endpoints that Resilience4j exposes for monitoring
        and management: /actuator/circuitbreakers, /actuator/retries,
        /actuator/ratelimiters, /actuator/bulkheads.
      endpoints:
        - "/actuator/circuitbreakers"
        - "/actuator/retries"
        - "/actuator/ratelimiters"
        - "/actuator/bulkheads"
        - "/actuator/health"
      related: ["monitoring", "Spring Boot"]

    - term: Micrometer
      definition: >-
        Application metrics facade used by Resilience4j to export resilience
        pattern metrics to monitoring systems like Prometheus, Grafana, and
        Datadog.
      related: ["monitoring", "metrics"]

    - term: FaultTolerance
      definition: >-
        The ability of a system to continue operating correctly in the presence
        of failures of some of its components. Resilience4j implements fault
        tolerance through circuit breakers, retries, rate limiters, and bulkheads.
      related: ["CircuitBreaker", "Retry", "RateLimiter", "Bulkhead"]