apache/pulsar · error · InvalidSchemaDataException

Unknown schema type :

Error message

Unknown schema type : 

What it means

The default branch of SchemaDataValidator.validateSchemaData throws InvalidSchemaDataException for any SchemaType the broker's validator switch does not recognize. It means the submitted schema type is not a storable/known server-side type in this broker version.

Source

Thrown at pulsar-broker/src/main/java/org/apache/pulsar/broker/service/schema/validator/SchemaDataValidator.java:100

                break;
            case NONE:
            case BYTES:
            case EXTERNAL:
                // `NONE`, `BYTES` and `EXTERNAL` schema is not stored
                break;
            case AUTO:
            case AUTO_CONSUME:
            case AUTO_PUBLISH:
                throw new InvalidSchemaDataException(
                    "Schema " + schemaData.getType() + " is a client-side schema type");
            case KEY_VALUE:
                KeyValue<SchemaData, SchemaData> kvSchema =
                    KeyValueSchemaCompatibilityCheck.decodeKeyValueSchemaData(schemaData);
                validateSchemaData(kvSchema.getKey(), allowLegacyJacksonFormat);
                validateSchemaData(kvSchema.getValue(), allowLegacyJacksonFormat);
                break;
            default:
                throw new InvalidSchemaDataException("Unknown schema type : " + schemaData.getType());
        }
    }

    /**
     * Validate a schema data is in a valid form.
     *
     * @param schemaData schema data to validate
     * @throws InvalidSchemaDataException if the schema data is not in a valid form.
     */
    void validate(SchemaData schemaData) throws InvalidSchemaDataException;

}

View on GitHub (pinned to 820761864e)

Solutions

1. Use a broker-supported SchemaType (AVRO, JSON, STRING, INT32, KEY_VALUE, PROTOBUF_NATIVE, NONE, ...); check org.apache.pulsar.common.schema.SchemaType for the list.
2. Upgrade the broker to at least the client's version if the type was introduced later (e.g. newer protobuf/avro-derived types).
3. Inspect the submitted SchemaInfo: ensure the type field is set explicitly and not defaulted to an unknown ordinal.
4. For custom formats, store them under an existing generic type (BYTES/EXTERNAL) rather than inventing a type.

Example fix

// before
SchemaInfo info = SchemaInfoImpl.builder().type(SchemaType.of(999))
    .data(data).build();
// after
SchemaInfo info = SchemaInfoImpl.builder().type(SchemaType.AVRO)
    .data(data).schemaProperties(props).build();

import org.apache.pulsar.common.schema.SchemaType;
import java.util.EnumSet;
private static final Set<SchemaType> STORABLE = EnumSet.of(
    SchemaType.NONE, SchemaType.STRING, SchemaType.AVRO, SchemaType.JSON,
    SchemaType.PROTOBUF_NATIVE, SchemaType.KEY_VALUE, SchemaType.INT8, SchemaType.INT16,
    SchemaType.INT32, SchemaType.INT64, SchemaType.FLOAT, SchemaType.DOUBLE,
    SchemaType.BOOLEAN, SchemaType.DATE, SchemaType.TIME, SchemaType.TIMESTAMP);
if (!STORABLE.contains(info.getType())) {
    throw new IllegalArgumentException("Unsupported schema type for registry: " + info.getType());
}

boolean knownStorableType(SchemaInfo info) {
    try { return info.getType() != null && info.getType() != SchemaType.NONE || true; }
    catch (IllegalArgumentException e) { return false; }
}

When it happens

Trigger: Submitting a SchemaInfo with an unrecognized or newer SchemaType value — e.g. a custom/undefined type ordinal from an older or newer client, a type enum that fails the switch (primitives, STRING, AVRO, JSON, PROTOBUF_NATIVE, KEY_VALUE etc. are handled), or corrupt type metadata in a hand-built SchemaInfo.

Common situations: Client broker version skew: a client built against a newer SchemaType enum sends a type the broker doesn't know; manual REST payloads with a bad integer type code; generated SchemaInfo from third-party tooling with the type field left unset or mis-set.

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

• Invalid schema definition data for primitive schemas :length
• deserialize ProtobufNative Schema failed
• protobuf root message descriptor is null, please recheck roo
• Schema ${schemaType} is a client-side schema type
• Invalid schema definition data for string schema : '

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/b97e230bb8810f10. Report an issue: GitHub.