apache/beam · error

failed to stage file

Error message

failed to stage file %v

What it means

stageFiles wraps the error from stageFile when staging a generic artifact file (URN graphx.URNArtifactFileType) fails after its path was successfully parsed from the ArtifactFilePayload. A non-EOF error means the file could not be opened or its chunks could not be sent over the staging stream.

Solutions

1. Check the wrapped error: if file open failed, verify the artifact path exists and is readable
2. Ensure all required dependencies/resources are included in the staging set
3. Retry on transient gRPC send errors (upper layer retries per attempt)
4. Verify disk space and permissions on the staging directory

Example fix

// before
return errors.Wrapf(err, "failed to stage file %v", typePl.GetPath())
// after: pre-check the file, e.g.
// if _, err := os.Stat(path); err != nil { return fmt.Errorf("artifact missing: %w", err) }

// pre-check all staged files exist and are readable
for _, f := range artifacts {
  fh, err := os.Open(f)
  if err != nil { return fmt.Errorf("artifact unreadable: %s: %w", f, err) }
  fh.Close()
}

if err := submit(...); err != nil && strings.Contains(err.Error(), "failed to stage file ") {
  // path is in err: verify it exists and retry on transient send errors
}

When it happens

Trigger: stageFile(typePl.GetPath(), stream) returns non-EOF: the artifact path does not exist locally, is unreadable, or stream.Send fails during chunked upload.

Common situations: Required artifacts (resources, extra packages) missing from the staging directory, permission problems on temp files, connection dropped mid-upload of large files.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• failed to stage Go worker binary
• chunk send failed
• expected header as first message
• failed to close stream for
• failed to receive header

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/ece59b0fd99bbfda. Report an issue: GitHub.

Appendix: source

Thrown at sdks/go/pkg/beam/runners/universal/runnerlib/stage.go:130

			// TODO(https://github.com/apache/beam/issues/21459): Legacy Type URN. If requested, provide the binary.
			// To be removed later in 2022, once thoroughly obsolete.
			case graphx.URNArtifactGoWorker:
				if err := stageFile(binary, stream); err != nil {
					if err == io.EOF {
						continue // so we can get the real error from stream.Recv.
					}
					return errors.Wrapf(err, "failed to stage Go worker binary: %v", binary)
				}
			case graphx.URNArtifactFileType:
				typePl := pipepb.ArtifactFilePayload{}
				if err := proto.Unmarshal(request.GetArtifact.Artifact.TypePayload, &typePl); err != nil {
					return errors.Wrap(err, "failed to parse artifact file payload")
				}
				if err := stageFile(typePl.GetPath(), stream); err != nil {
					if err == io.EOF {
						continue // so we can get the real error from stream.Recv.
					}
					return errors.Wrapf(err, "failed to stage file %v", typePl.GetPath())

				}
			default:
				return errors.Errorf("request has unexpected artifact type %s", typeUrn)
			}

		default:
			return errors.Errorf("request has unexpected type %T", request)
		}
	}
}

func stageFile(filename string, stream jobpb.ArtifactStagingService_ReverseArtifactRetrievalServiceClient) error {
	fd, err := os.Open(filename)
	if err != nil {
		return errors.Wrapf(err, "unable to open file %v", filename)
	}
	defer fd.Close()

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