apache/beam · error · RuntimeException

Unable to parse schema for RowCoder:

Error message

Unable to parse schema for RowCoder: 

What it means

When translating a RowCoder from its proto form, CoderTranslators.fromComponents parses the payload as a Schema protobuf; an InvalidProtocolBufferException is rethrown as RuntimeException('Unable to parse schema for RowCoder: '), meaning the coder payload bytes are corrupt or not a Schema message.

Source

Thrown at sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/CoderTranslators.java:181

      public List<? extends Coder<?>> getComponents(RowCoder from) {
        return ImmutableList.of();
      }

      @Override
      public byte[] getPayload(RowCoder from) {
        return SchemaTranslation.schemaToProto(from.getSchema(), true).toByteArray();
      }

      @Override
      public RowCoder fromComponents(
          List<Coder<?>> components, byte[] payload, CoderTranslation.TranslationContext context) {
        checkArgument(
            components.isEmpty(), "Expected empty component list, but received: " + components);
        Schema schema;
        try {
          schema = SchemaTranslation.schemaFromProto(SchemaApi.Schema.parseFrom(payload));
        } catch (InvalidProtocolBufferException e) {
          throw new RuntimeException("Unable to parse schema for RowCoder: ", e);
        }
        return RowCoder.of(schema);
      }
    };
  }

  static <T> CoderTranslator<SchemaCoder<T>> schema() {
    return new CoderTranslator<SchemaCoder<T>>() {
      private static final String TO_ROW_FUNCTION_URN = "beam:torowfn:javasdk:v1";
      private static final String FROM_ROW_FUNCTION_URN = "beam:fromrowfn:javasdk:v1";
      private static final String TYPE_DESCRIPTOR_URN = "beam:typedescriptor:javasdk:v1";

      @Override
      public ImmutableList<? extends Coder<?>> getComponents(SchemaCoder<T> from) {
        return ImmutableList.of();
      }

      @Override

View on GitHub (pinned to 12126d8942)

Solutions

1. Re-serialize the pipeline with the same Beam version used to run it; align SDK versions
2. Verify the payload bytes are a valid SchemaApi.Schema protobuf (parse standalone to confirm)
3. Regenerate the job graph rather than reusing stale/cached serialized pipelines
4. If decode must be lenient, wrap and log payload hex to diagnose the exact corruption

Example fix

// before
schema = SchemaTranslation.schemaFromProto(SchemaApi.Schema.parseFrom(payload));
// after
try {
  schema = SchemaTranslation.schemaFromProto(SchemaApi.Schema.parseFrom(payload));
} catch (InvalidProtocolBufferException e) {
  throw new IOException("Unable to parse RowCoder schema payload (" + payload.length + " bytes)", e);
}

SchemaApi.Schema.parseFrom(payload); // throws InvalidProtocolBufferException if invalid

try {
  return CoderTranslators.rowCoderFromProtoComponents(payload, components);
} catch (RuntimeException e) {
  if (e.getMessage().startsWith("Unable to parse schema for RowCoder")) {
    throw new IOException("corrupt RowCoder payload; regenerate the pipeline proto", e);
  }
  throw e;
}

When it happens

Trigger: Deserializing a pipeline/graph proto whose RowCoder spec payload was truncated, corrupted, or produced by an incompatible Beam version where the payload layout differs.

Common situations: Pipelines serialized by a different Beam SDK version and replayed with another; hand-edited or damaged job protos; transport layers that mangle binary payloads.

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.

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Missing serialized typeDescriptor
• Failed to convert PipelineOptions to JSON
• Internal error determining boundedness of Read
• Required field 'timestamp_transform' not set in %s
• Required field 'trigger' not set in %s

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/42e2f3799d20e51c. Report an issue: GitHub.