gofiber/fiber · error

limiter: failed to get key

Error message

limiter: failed to get key %q from storage: %w

What it means

The rate-limiter manager wraps the underlying fiber.Storage backend (e.g. Redis, MySQL, SQLite, Memory) and surfaces any read failure from storage.GetWithContext as this error. The key in the message is passed through logKey(), which redacts it when shouldRedactKeys is enabled. The original storage error is preserved via %w so errors.Is/As can unwrap it.

Solutions

1. Inspect the wrapped error with errors.Unwrap to identify the storage-layer cause (e.g. redis: connection refused, context deadline exceeded).
2. Verify the storage backend is reachable from the app host: redis-cli ping, mysql ping, or the storage driver's health check.
3. Check that the fiber.Storage instance passed to limiter.New was successfully initialized and its connection pool is sized for peak RPS (each limiter check does at least one Get + one Set).
4. If context cancellation is the cause, move the limiter earlier in the chain or raise the request timeout so storage I/O can complete.
5. Enable storage-level retries / connection healing on the storage implementation itself (the limiter does not retry).

Example fix

// before: storage wired but unchecked, errors bubble as 500
app.Use(limiter.New(limiter.Config{Storage: redisStore}))

// after: confirm storage readiness at startup and log the wrapped cause
if err := redisStore.Ping(); err != nil { log.Fatalf("limiter storage unreachable: %v", err) }
app.Use(limiter.New(limiter.Config{Storage: redisStore}))

// Before mounting the limiter, probe the storage backend.
if err := store.Ping(); err != nil {
    return fmt.Errorf("limiter storage unhealthy: %w", err)
}

// In the handler, fall back gracefully on storage errors.
if err := c.Next(); err != nil {
  var le *limiter.Error // hypothetical; otherwise match on the wrapped prefix
  if errors.Is(err, storage.ErrConn) { return c.Status(503).SendString("rate limit unavailable") }
  return err
}

When it happens

Trigger: Calling any limiter middleware backed by a non-nil fiber.Storage when GetWithContext returns a non-nil error. Concrete triggers: Redis connection lost or DENIED, MySQL gone-away, context cancelled before the storage read completes, expired storage credentials, TLS handshake failure to the storage endpoint, or a misregistered storage driver.

Common situations: Production deploy where Redis was restarted or network-partitioned; storage conn-pool exhausted under burst traffic; request context already cancelled by client disconnect before the limiter runs; misconfigured STORAGE_URL env var pointing at the wrong host; storage schema migration that broke the previous connection string.

Related errors

• limiter: failed to store key
• limiter: failed to persist state
• limiter: failed to persist state
• cache: failed to delete key
• cache: failed to reload key

AI-assisted analysis of gofiber/fiber@a105acad6c (2026-08-11). Data as JSON: /api/errors/f592ab35be81fe2d. Report an issue: GitHub.

Appendix: source

Thrown at middleware/limiter/manager.go:70

// acquire returns an *entry from the sync.Pool
func (m *manager) acquire() *item {
	return m.pool.Get().(*item) //nolint:forcetypeassert,errcheck // We store nothing else in the pool
}

// release and reset *entry to sync.Pool
func (m *manager) release(e *item) {
	e.prevHits = 0
	e.currHits = 0
	e.exp = 0
	m.pool.Put(e)
}

// get data from storage or memory
func (m *manager) get(ctx context.Context, key string) (*item, error) {
	if m.storage != nil {
		raw, err := m.storage.GetWithContext(ctx, key)
		if err != nil {
			return nil, fmt.Errorf("limiter: failed to get key %q from storage: %w", m.logKey(key), err)
		}
		if raw != nil {
			it := m.acquire()
			if _, err := it.UnmarshalMsg(raw); err != nil {
				m.release(it)
				return nil, fmt.Errorf("limiter: failed to unmarshal key %q: %w", m.logKey(key), err)
			}
			return it, nil
		}
		return m.acquire(), nil
	}

	value := m.memory.Get(key)
	if value == nil {
		return m.acquire(), nil
	}

	it, ok := value.(*item)

View on GitHub (pinned to a105acad6c)