gofiber/fiber · error

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

Error message

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

What it means

Returned by manager.get (manager.go:68-71) when Storage.GetWithContext fails while loading the counter for a rate-limit key. This is the upstream cause that propagates through both FixedWindow and SlidingWindow handlers; the manager wraps it with the key (redacted if DisableValueRedaction is false).

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 9a4c7e57fe)

Solutions

1. Healthcheck Storage at startup and on an interval; fail fast on misconfiguration.
2. Tune the storage connection pool size to match peak RPS — under-sizing causes Get timeouts.
3. Verify KeyGenerator output is within the storage's key-size rules.
4. Wrap the limiter to fail open on storage errors if rate limiting is best-effort for your service.

Example fix

// before
app.Use(limiter.New(limiter.Config{Storage: redis.New()}))

// after — validated pool + fail-open around limiter errors
store := redis.New(redis.Config{PoolSize: 128})
app.Use(func(c fiber.Ctx) error {
    err := limiter.New(limiter.Config{Storage: store})(c)
    if err != nil {
        log.Printf("limiter storage get failed: %v — fail open", err)
        return c.Next()
    }
    return nil
})

// startup storage read check
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
defer cancel()
if _, err := store.GetWithContext(ctx, "__hc__"); err != nil {
    log.Fatalf("limiter storage unreadable: %v", err)
}

// fail open on storage read errors so rate-limit outages don't take the app down
app.Use(func(c fiber.Ctx) error {
    if err := limiterHandler(c); err != nil {
        log.Printf("limiter storage read failed: %v — fail open", err)
        return c.Next()
    }
    return nil
})

When it happens

Trigger: Remote Storage (Redis/MySQL/Mongo/etc.) returns an error on GetWithContext: connection lost, query deadline exceeded, auth failure mid-run, or context cancelled. A cache miss returns (nil, nil) and does NOT trigger this — only an actual error does.

Common situations: Storage restart during traffic; TLS cert rotated without reloading the app; network partition to the storage pod; KeyGenerator producing keys that overflow storage key-size limits and trigger backend errors.

Related errors

• limiter: failed to store key %q: %w
• cache: failed to reload key %q after eviction failure: %w
• cache: failed to delete expired key %q: %w
• cache: failed to get key %q from storage: %w
• cache: failed to get raw key %q from storage: %w

AI-assisted analysis of gofiber/fiber@9a4c7e57fe (2026-08-04). Data as JSON: /data/errors/f592ab35be81fe2d.json. Report an issue: GitHub.