gofiber/fiber · error

cache: failed to get raw key

Error message

cache: failed to get raw key %q from storage: %w

What it means

Returned by manager.getRaw (the raw-body fetch path) when an external Storage's GetWithContext errors. Parallel to error 141 but for the separated raw response body (key+"_body") stored alongside the msgp metadata entry when cfg.Storage is configured.

Solutions

1. Examine the wrapped error to classify (network vs context-cancellation vs protocol).
2. Verify Storage health, connection pool, and timeouts.
3. If intermittent, treat as cache miss and serve from the handler rather than failing the request.
4. Ensure the raw-body key namespace is not evicted independently of the metadata key (consistent TTLs).

Example fix

// before
raw, err := m.storage.GetWithContext(ctx, key)
if err != nil {
    return nil, fmt.Errorf("cache: failed to get raw key %q from storage: %w", m.logKey(key), err)
}

// after: degrade to miss on transient storage errors
raw, err := m.storage.GetWithContext(ctx, key)
if err != nil {
    if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
        return nil, err
    }
    return nil, errCacheMiss
}

// Verify the raw-body namespace is writable/readable before serving.
func probeRawBody(ctx context.Context, s fiber.Storage) error {
    k := "__probe_body"
    if err := s.SetWithContext(ctx, k, []byte("x"), time.Second); err != nil {
        return err
    }
    if _, err := s.GetWithContext(ctx, k); err != nil {
        return err
    }
    return s.DeleteWithContext(ctx, k)
}

raw, err := m.storage.GetWithContext(ctx, key)
if err != nil {
    if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
        return nil, err
    }
    log.Warn("raw-body fetch failed, treating as miss:", err)
    return nil, errCacheMiss
}

When it happens

Trigger: Cache lookup on an external-Storage deployment where the body was stored separately; Storage.GetWithContext fails for the *_body key: backend down, timeout, connection error, context cancellation.

Common situations: Same as 141 — Redis/storage outage, pool exhaustion, client disconnect propagating context cancellation, TLS/auth issues, failover. Surfaces specifically on the second leg of a two-key cache lookup.

Related errors

• cache: failed to store raw key
• cache: failed to delete key
• cache: failed to get key
• cache: failed to store key
• cache: failed to delete raw key

AI-assisted analysis of gofiber/fiber@a105acad6c (2026-08-11). Data as JSON: /api/errors/70a9641c5bb2fe5b. Report an issue: GitHub.

Appendix: source

Thrown at middleware/cache/manager.go:145

	}

	if value := m.memory.Get(key); value != nil {
		it, ok := value.(*item)
		if !ok {
			return nil, fmt.Errorf("cache: unexpected entry type %T for key %q", value, m.logKey(key))
		}
		return it, nil
	}

	return nil, errCacheMiss
}

// get raw data from storage or memory
func (m *manager) getRaw(ctx context.Context, key string) ([]byte, error) {
	if m.storage != nil {
		raw, err := m.storage.GetWithContext(ctx, key)
		if err != nil {
			return nil, fmt.Errorf("cache: failed to get raw key %q from storage: %w", m.logKey(key), err)
		}
		if raw == nil {
			return nil, errCacheMiss
		}
		return raw, nil
	}

	if value := m.memory.Get(key); value != nil {
		raw, ok := value.([]byte)
		if !ok {
			return nil, fmt.Errorf("cache: unexpected raw entry type %T for key %q", value, m.logKey(key))
		}
		return raw, nil
	}

	return nil, errCacheMiss
}

View on GitHub (pinned to a105acad6c)