技能檔案

Go Resilience

Name: Go Resilience
Author: 333-333-333

Resilience patterns for Go microservices: circuit breaker, retry with backoff, timeouts, graceful degradation, and failure injection testing. Trigger: When implementing circuit breakers, adding retry logic, configuring timeouts, or testing service resilience under failure.

333-333-3330 星標2026年2月9日

職業
分類: 架構模式

技能內容

When to Use

Service calls external providers (FCM, SendGrid, Twilio, Flow.cl)
Need to handle transient failures gracefully
Want to prevent cascading failures when a dependency is down
Configuring timeouts at HTTP, database, and external call levels
Testing that the service degrades gracefully under failure

Critical Patterns

The Three Pillars

Every external call should be wrapped with these three patterns, in order:

Request → Timeout → Retry (with backoff) → Circuit Breaker → External Service

Timeout: Every external call has a context timeout — never wait forever
Retry with Backoff: Retry transient failures with exponential delay + jitter
Circuit Breaker: Stop calling a failing dependency after N consecutive failures

相關技能

Go Resilience | Skills Pool

Layer	Timeout	Where
HTTP server read/write	30s	`http.Server{ReadTimeout, WriteTimeout}`
External HTTP calls	5-10s	`context.WithTimeout` per call
Database queries	5s	`context.WithTimeout` per query
Graceful shutdown	10s	`srv.Shutdown(ctx)`

CLOSED  ──(N failures)──▶  OPEN  ──(cooldown)──▶  HALF-OPEN
   ▲                                                   │
   └──────────(success)────────────────────────────────┘
   └──────────(failure)──▶  OPEN (reset cooldown)

Attempt 1: immediate
Attempt 2: 100ms + jitter
Attempt 3: 200ms + jitter
Attempt 4: 400ms + jitter
...capped at maxDelay

Scenario	How to test	Expected behavior
Provider timeout	Mock sender with `time.Sleep` > timeout	Returns error, resource marked as failed
Provider 5xx	Mock sender returns error	Circuit breaker opens after N failures
DB connection lost	Stop testcontainer mid-test	Returns 503 on /ready, 200 on /health
Memory pressure	k6 soak test for 30min+	No memory growth, stable response times
Connection pool exhaustion	Load test > pool.MaxConns	Requests queue, don't crash

Service calls external provider?
  → Wrap with timeout + retry + circuit breaker

Provider is down?
  → Circuit breaker opens, fail fast, degrade gracefully

Transient network error?
  → Retry with exponential backoff + jitter

Database query?
  → Add context.WithTimeout (5s default)

HTTP server?
  → Set ReadTimeout + WriteTimeout (30s default)

File	Description
`assets/circuit_breaker.go`	Lightweight circuit breaker with closed/open/half-open states
`assets/retry.go`	Retry with exponential backoff and jitter
`assets/resilient_sender.go`	Wrapper combining circuit breaker + retry + timeout
`assets/resilience_test.go`	Unit tests for resilience patterns (timeout, failure injection)

Don't	Do
Call external services without timeout	Always `context.WithTimeout`
Retry without backoff	Exponential backoff + jitter
Retry non-idempotent operations	Only retry idempotent calls (GET, or operations with idempotency keys)
Ignore circuit breaker state	Log state changes, expose in metrics
No fallback when circuit is open	Return cached result, queue for later, or return graceful error
Test only happy path	Inject failures: timeout, 5xx, connection refused

Go Resilience

When to Use

Critical Patterns

The Three Pillars

Go Resilience

When to Use

Critical Patterns

The Three Pillars

Timeout Configuration

Circuit Breaker

Retry with Exponential Backoff

Resilient Sender Wrapper

Testing Resilience

Decision Tree

Assets

Anti-Patterns

Sessions

Docker Patterns

Autonomous Loops

Kotlin Patterns

Eval Harness

Golang Patterns