@bernierllc/nevar-circuit-breaker

Circuit breaker for the Nevar rules engine suite. Provides configurable hard limits for cascade depth, actions per chain, chain duration, and concurrent chain execution.

Installation

npm install @bernierllc/nevar-circuit-breaker

Usage

import { CircuitBreaker } from '@bernierllc/nevar-circuit-breaker';

const breaker = new CircuitBreaker({
  maxCascadeDepth: 5,
  maxActionsPerChain: 25,
  maxChainDurationMs: 10_000,
  maxConcurrentChains: 50,
});

// Check limits before proceeding
breaker.checkDepth(currentDepth);
breaker.checkActions(actionCount);
breaker.checkDuration(startTime);

// Manage concurrency
if (breaker.acquireChain()) {
  try {
    // ... execute chain
  } finally {
    breaker.releaseChain();
  }
}

API

CircuitBreaker

Enforces hard limits on rule chain execution to prevent runaway cascades.

Constructor: new CircuitBreaker(config?: Partial<CircuitBreakerConfig>)

Default config: maxCascadeDepth: 10, maxActionsPerChain: 50, maxChainDurationMs: 30000, maxConcurrentChains: 100

• checkDepth(currentDepth) - Throws NevarCircuitBreakerError if depth exceeds maxCascadeDepth
• checkActions(actionCount) - Throws NevarCircuitBreakerError if count exceeds maxActionsPerChain
• checkDuration(startTime) - Throws NevarCircuitBreakerError if elapsed time exceeds maxChainDurationMs
• acquireChain() - Attempts to acquire a concurrency slot. Returns true if under limit, false if at capacity
• releaseChain() - Releases a concurrency slot
• getConfig() - Returns a copy of the current configuration
• getActiveChains() - Returns the number of currently active chains

Integration Documentation

Logger Integration

This package does not integrate with @bernierllc/logger. As a core package, logger integration is optional and not included by default. Consumers should handle logging at the service layer.

NeverHub Integration

This package does not integrate with @bernierllc/neverhub-adapter. As a core package, NeverHub integration is not applicable. NeverHub registration should be handled by service-layer packages that compose this package.