apache/beam · error · RuntimeException

Unable to infer configuration row from configuration proto a

Error message

Unable to infer configuration row from configuration proto and schema.

What it means

ExternalSchemaIOTransformRegistrar.translateRow decodes the configuration bytes from the transform proto using a RowCoder built from the declared config schema. If the bytes do not match the schema (decode fails with IOException), it wraps the failure in this RuntimeException. It indicates the serialized configuration payload and the schema are inconsistent.

Source

Thrown at sdks/java/extensions/schemaio-expansion-service/src/main/java/org/apache/beam/sdk/extensions/schemaio/expansion/ExternalSchemaIOTransformRegistrar.java:121

      return null;
    }

    try {
      SchemaApi.Schema protoSchema = SchemaApi.Schema.parseFrom(schemaBytes);
      return SchemaTranslation.schemaFromProto(protoSchema);
    } catch (InvalidProtocolBufferException e) {
      throw new RuntimeException("Unable to infer data schema from configuration proto.", e);
    }
  }

  private static Row translateRow(byte[] rowBytes, Schema configSchema) {
    RowCoder rowCoder = RowCoder.of(configSchema);
    InputStream stream = new ByteArrayInputStream(rowBytes);

    try {
      return rowCoder.decode(stream);
    } catch (IOException e) {
      throw new RuntimeException(
          "Unable to infer configuration row from configuration proto and schema.", e);
    }
  }

  @VisibleForTesting
  static class ReaderBuilder
      implements ExternalTransformBuilder<Configuration, PBegin, PCollection<Row>> {
    SchemaIOProvider schemaIOProvider;

    ReaderBuilder(SchemaIOProvider schemaIOProvider) {
      this.schemaIOProvider = schemaIOProvider;
    }

    @Override
    public PTransform<PBegin, PCollection<Row>> buildExternal(Configuration configuration) {
      return schemaIOProvider
          .from(
              configuration.location,

View on GitHub (pinned to 12126d8942)

Solutions

1. Ensure the SDK and expansion service versions match so the config schema used to encode equals the one used to decode.
2. Re-generate the transform payload with the current SDK (rebuild/re-submit the pipeline) instead of reusing cached expansion responses.
3. Inspect the nested IOException (getCause) to find the exact field/type mismatch and fix the config payload accordingly.
4. If constructing the proto manually, verify every schema field is set with the correct type before calling translateRow.

Example fix

// before
ExpansionRequest request = loadCachedRequest(); // built with old schema
Row row = registrar.translateRow(request.getConfigSchema(), request.getConfigRow().toByteArray());
// after
ExpansionRequest request = fetchFreshRequestFromExpansionService(); // schema in sync with runtime
Row row = registrar.translateRow(request.getConfigSchema(), request.getConfigRow().toByteArray());

// Before decoding, check schema/byte consistency
if (rowBytes == null || rowBytes.length == 0) throw new IllegalArgumentException("empty config row bytes");
RowCoder.of(configSchema).verifyDeterministic(); // also validates schema is well-formed

try { return rowCoder.decode(new ByteArrayInputStream(rowBytes)); }
catch (IOException e) { LOG.error("config row does not match schema {}", configSchema, e); throw new RuntimeException("...", e); }

When it happens

Trigger: Calling ExternalSchemaIOTransformRegistrar.translateRow with config bytes from the expansion request proto that do not conform to configSchema; schema evolved on one side (producer wrote rows with an older/newer schema) while the registrar decodes with the current schema; corrupted or truncated rowBytes.

Common situations: A pipeline was built with an older Beam SDK and submitted against a newer expansion service (or vice versa) so the config schema changed between serialize and deserialize; hand-crafted cross-language transforms passing malformed config protos; staging old jars with the pipeline.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• Expected a Java primitive value but received
• Could not decode the value from Row
• AVRO schema doesn't match row schema. Row schema ${beamSchem
• Illegal access to pipeline after visitor traversal was compl
• Pipeline update will not be possible because the following t

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/9275ca5aa7ecea8c. Report an issue: GitHub.