nestjs-resilience

Wire @dudousxd/nestjs-resilience into NestJS DI — ResilienceModule.forRoot/forRootAsync (global by default), the injectable ResilienceService (execute, failover, circuit(key).snapshot()/reset()), and the @Timeout / @Retry / @CircuitBreaker method decorators wrapped at startup by the ResilienceExplorer via DiscoveryService. Use for module registration, async store config, named policy registries, the RESILIENCE_STORE / RESILIENCE_OPTIONS tokens, default breaker keys (Class.method), and emit/eventEmitter.

Programmatic resilience policies in @dudousxd/nestjs-resilience — timeout(ms), retry({ attempts, backoff }), exponential(baseMs), circuitBreaker({ key, store, threshold, cooldownMs, halfOpenMax }), wrap(...policies) composing outer→inner, and the standalone failover({ targets, run }) function. Use for composing timeout/retry/circuit-breaker around any async call, picking composition order, honoring the AbortSignal in PolicyContext, exponential backoff, BrokenCircuitError/TimeoutError, and choosing a ResilienceStore. Covers the Policy / PolicyContext / Operation contracts.

The ResilienceStore contract in @dudousxd/nestjs-resilience — admit(key, cfg), record(key, cfg, ok, probe), snapshot(key) — and its atomicity rule (exactly one half-open probe under load). Use to pick a store (InMemoryResilienceStore for single-process, RedisResilienceStore/SQL for fleets), build a SQL-backed store with SqlResilienceStore + CIRCUITS_DDL + SqlDriver, understand BreakerConfig / Admission / CircuitSnapshot / CircuitStatus, and validate a custom store with runResilienceStoreContract.

RedisResilienceStore — a distributed circuit-breaker ResilienceStore for @dudousxd/nestjs-resilience backed by Redis (ioredis) with atomic Lua admit/record (cbAdmit / cbRecord). Use to share breaker state across many NestJS instances, wire it via ResilienceModule.forRoot({ store }), set a keyPrefix, inject an ioredis client, and rely on the fleet-wide exactly-one-half-open-probe guarantee. Covers RedisResilienceStoreOptions (clock, keyPrefix) and the ioredis peer dependency.

nestjsResilienceTelescope() — a @dudousxd/nestjs-telescope extension for @dudousxd/nestjs-resilience that records aviary:resilience:* diagnostics events (circuit-opened/closed/half-open, short-circuited, failover, timeout, retry) as `resilience` Telescope entries and adds a Resilience dashboard (open circuits, failovers, most-tripped circuits, recent transitions). Use to register it in TelescopeModule.forRoot({ extensions }), tune topKeysLimit/recentLimit, and ensure resilience emit + diagnostics are enabled. Exposes ResilienceWatcher, buildResilienceEntry, RESILIENCE_ENTRY_TYPE.