apache/beam · error · GoogleJsonResponseException

${msg}

Error message

${msg}

What it means

checkSchemaPredicate throws a GoogleJsonResponseException with HTTP 412 Precondition Failed when the predicate is false. It is the fake's way of reporting BigQuery precondition failures (typically schema conflicts) with a caller-supplied message.

Solutions

1. Make the schema change BigQuery-compatible (add optional fields, never change/remove existing field types or modes)
2. Fetch the current table schema first and merge the new fields with the existing ones
3. Catch GoogleJsonResponseException and inspect the 412 status plus message to identify the violated precondition

Example fix

// before
schema.update(Set.of(Field.newBuilder("f", LegacySQLTypeName.INTEGER).build())); // 412
// after
// keep existing field 'f', only add new nullable fields
TableSchema merged = mergeFields(existingSchema, newFields);
service.updateTableSchema(tableRef, merged);

// Compare your new schema against the fetched one before updating
Table current = service.getTable(tableRef);
for (Field f : newFields) {
  Field existing = current.getSchema().getFields().stream()
      .filter(x -> x.getName().equals(f.getName())).findFirst().orElse(null);
  if (existing != null && (existing.getType() != f.getType() || existing.getMode() != f.getMode())) {
    throw new IllegalArgumentException("illegal schema change on field: " + f.getName());
  }
}

try {
  service.updateTableSchema(tableRef, newSchema);
} catch (GoogleJsonResponseException e) {
  if (e.getStatusCode() == 412) {
    throw new SchemaPreconditionFailedException(e.getDetails(), e);
  }
  throw e;
}

When it happens

Trigger: checkSchemaChangesProtos detecting an incompatible schema change (e.g. modifying a REQUIRED/REPEATED field, changing a field type) via update/patch table schema calls.

Common situations: Tests or code updating a table schema in a way BigQuery would reject: narrowing a field type, making an optional field required, changing mode.

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

• bigquery write error
• Both a query and an output type of 'BEAM_ROW' were…
• Conflicting field modes for field
• Conflicting field types for field
• Converting BigQuery type

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/10c9ae00e1d4e40c. Report an issue: GitHub.

Appendix: source

Thrown at sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/testing/FakeDatasetService.java:441

        throwNotFound("Tried to get a table %s, but no such table existed", tableReference);
      }
      checkSchemaChanges(tableContainer.table.getSchema().getFields(), tableSchema.getFields());
      tableContainer.table.setSchema(tableSchema);

      for (Stream stream : writeStreams.values()) {
        if (stream.tableContainer == tableContainer) {
          stream.setUpdatedSchema(tableSchema);
        }
      }
    }
  }

  @FormatMethod
  void checkSchemaPredicate(boolean predicate, String msgFormat, Object... args)
      throws IOException {
    String msg = String.format(msgFormat, args);
    if (!predicate) {
      throw new GoogleJsonResponseException(
          new HttpResponseException.Builder(
              HttpStatusCodes.STATUS_CODE_PRECONDITION_FAILED, msg, new HttpHeaders()),
          null);
    }
  }

  private void checkSchemaChanges(
      List<TableFieldSchema> oldSchema, List<TableFieldSchema> newSchema) throws IOException {
    List<com.google.cloud.bigquery.storage.v1.TableFieldSchema> oldSchemaProtos =
        oldSchema.stream()
            .map(TableRowToStorageApiProto::tableFieldToProtoTableField)
            .collect(Collectors.toList());

    List<com.google.cloud.bigquery.storage.v1.TableFieldSchema> newSchemaProtos =
        newSchema.stream()
            .map(TableRowToStorageApiProto::tableFieldToProtoTableField)
            .collect(Collectors.toList());
    checkSchemaChangesProtos(oldSchemaProtos, newSchemaProtos);

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