apache/beam · error

invalid WindowInto payload for %v

Error message

invalid WindowInto payload for %v

What it means

When translating a URNWindow (WindowInto) transform, the raw payload bytes must unmarshal into pipepb.WindowIntoPayload. Failure means the payload bytes are not a valid WindowIntoPayload protobuf, so the windowing strategy cannot be reconstructed and translation aborts.

Source

Thrown at sdks/go/pkg/beam/core/runtime/exec/translate.go:786

			_, w, err := b.makeCoderForPCollection(pid)
			if err != nil {
				return nil, err
			}
			preservedCoderID := tp.GetReshuffle().GetCoderId()
			pc, err := unmarshalReshuffleCoders(preservedCoderID, tp.GetReshuffle().GetCoderPayloads())
			if err != nil {
				return nil, err
			}
			u = &ReshuffleOutput{UID: b.idgen.New(), Coder: coder.NewW(pc, w), Out: out[0]}

		default:
			return nil, errors.Errorf("unexpected payload: %v", &tp)
		}

	case graphx.URNWindow:
		var wp pipepb.WindowIntoPayload
		if err := proto.Unmarshal(payload, &wp); err != nil {
			return nil, errors.Wrapf(err, "invalid WindowInto payload for %v", transform)
		}
		wfn, err := unmarshalWindowFn(wp.GetWindowFn())
		if err != nil {
			return nil, err
		}
		u = &WindowInto{UID: b.idgen.New(), Fn: wfn, Out: out[0]}

	case graphx.URNMapWindows:
		var fn pipepb.FunctionSpec
		if err := proto.Unmarshal(payload, &fn); err != nil {
			return nil, errors.Wrapf(err, "invalid SideInput payload for %v", transform)
		}
		mapper, err := unmarshalAndMakeWindowMapping(&fn)
		if err != nil {
			return nil, err
		}
		u = &MapWindows{UID: b.idgen.New(), Fn: mapper, Out: out[0], FnUrn: fn.GetUrn()}

View on GitHub (pinned to 12126d8942)

Solutions

1. Resubmit the pipeline from an unmodified Beam SDK so the WindowInto payload is serialized correctly
2. Verify the payload bytes decode with `proto.Unmarshal(payload, &pipepb.WindowIntoPayload{})` offline
3. Upgrade SDK versions on both builder and harness sides to ensure schema compatibility

Example fix

null

var wp pipepb.WindowIntoPayload
if err := proto.Unmarshal(payload, &wp); err != nil {
	return fmt.Errorf("payload is not a WindowIntoPayload: %w", err)
}

null

if _, err := graph.MakePipeline(pipelineProto); err != nil {
	if strings.Contains(err.Error(), "invalid WindowInto payload") {
		// rebuild and resubmit the pipeline from a stock SDK
	}
}

When it happens

Trigger: WindowInto payload bytes corrupted in the job proto, a payload generated by a foreign runner not using the Beam proto schema, or a misrouted payload (e.g. FunctionSpec bytes passed where WindowIntoPayload is expected).

Common situations: Custom runners crafting pipeline protos by hand; cross-language/cross-version pipelines; payloads altered by proxies or serialized job caches.

Understand the failure class

Background: "cannot parse invalid wire-format data", "cannot unmarshal", "failed unmarshalling": protobuf unmarshal errors explained — this error's family across 10 libraries.

Related errors

• invalid SideInput payload for %v
• empty type
• invalid scope
• invalid input pcollection
• unwindowed coder %v on DataSource %v: %v

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/08b08b820e463730. Report an issue: GitHub.