Playground

This page runs the actual @nodelibraries/resilience library in your browser. Tune the flaky dependency on the left, switch strategies on and off, press Start and watch each request in the timeline. Statistics come from createStatsover a 10-second rolling window. Timing is real; the same seed replays the same sequence of failures and latencies.

StartResetSend oneSeed

Requests / s

10

Flaky dependency

Failure rate

20%

Base latency

120 ms

Latency jitter

+0…200 ms

Outage Slowdown ×5

Fallback

Cache

ttl

1 s

Bulkhead (concurrency limiter)

Permits

10

Retry

maxRetryAttempts

3

delay

100 ms

Circuit breaker

failureRatio

50%

breakDuration

5 s

Hedging

delay

300 ms

Timeout (per attempt)

timeout

500 ms

Changing a strategy rebuilds the pipeline (breaker state starts closed again).

Circuit:closed0 in flight

Circuit closed.

–OK incl. fallback (10 s)

–p50 latency

–p99 latency

0Retries

0Timeouts

0Rejections

0Fallbacks

0Total calls

Timeline (last 240 requests)

• success
• recovered (retry / hedge)
• cache hit
• fallback
• timeout
• rejected (circuit / bulkhead)
• failed

Most recent finished requests

#	Result	Attempts	Latency

Your pipeline

≈ 6.8 KB min+gzip (estimate)Copy

import { PipelineBuilder, fallbackStrategy, retryStrategy, circuitBreakerStrategy, timeoutStrategy } from '@nodelibraries/resilience';

// Strategies run in the order they are added: the first is the outermost.
const pipeline = new PipelineBuilder<User>()
  .add(fallbackStrategy({ fallbackValue: cachedUser }))
  .add(retryStrategy({ maxRetryAttempts: 3, backoffType: 'exponential', delay: 100, useJitter: true }))
  .add(circuitBreakerStrategy({ failureRatio: 0.5, minimumThroughput: 10, samplingDuration: '10s', breakDuration: 5000 }))
  .add(timeoutStrategy(500))
  .build();

const user = await pipeline.execute(({ signal }) => fetchUser(42, { signal }));