apache/pulsar · error · AvroRuntimeException

Schema typed [<schema.getClass().getName()>], simple-type:[<

Error message

Schema typed [<schema.getClass().getName()>], simple-type:[<schema.getType()>] is not supported. schema-content: <schema>

What it means

GenericSchemaImpl's constructor extracts field names/positions from the underlying Avro schema via schema.getFields(). If the schema object does not support Avro field access, Avro throws AvroRuntimeException, which is rethrown with a rewritten message naming the schema class, simple type, and content. It means the supplied schema cannot be used as an Avro generic record schema.

Source

Thrown at pulsar-client/src/main/java/org/apache/pulsar/client/impl/schema/generic/GenericSchemaImpl.java:51

 * we suggest migrate GenericSchemaImpl.of() to  <GenericSchema Implementor>.of() method
 * (e.g. GenericJsonSchema 、GenericAvroSchema )
 */
public abstract class GenericSchemaImpl extends AvroBaseStructSchema<GenericRecord>
        implements GenericSchema<GenericRecord> {

    protected final List<Field> fields;

    protected GenericSchemaImpl(SchemaInfo schemaInfo) {
        super(schemaInfo);

        try {
            this.fields = schema.getFields()
                    .stream()
                    .map(f -> new Field(f.name(), f.pos()))
                    .collect(Collectors.toList());
        } catch (AvroRuntimeException avroRuntimeException) {
            // Rewrite error log.
            throw new AvroRuntimeException("Schema typed [" + schema.getClass().getName() + "], simple-type:["
                    + schema.getType() + "] is not supported. schema-content: " + schema);
        }
    }

    @Override
    public List<Field> getFields() {
        return fields;
    }

    /**
     * Create a generic schema out of a <tt>SchemaInfo</tt>.
     *  warning : we suggest migrate GenericSchemaImpl.of() to  <GenericSchema Implementor>.of() method
     *  (e.g. GenericJsonSchema 、GenericAvroSchema )
     * @param schemaInfo schema info
     * @return a generic schema instance
     */
    public static GenericSchemaImpl of(SchemaInfo schemaInfo) {
        return of(schemaInfo, true);

View on GitHub (pinned to 820761864e)

Solutions

1. Verify the schema is an Avro RECORD type before wrapping it in GenericSchemaImpl
2. Check the schema content printed in the message for malformed JSON/Avro syntax
3. Use SchemaInfo with a valid record-type Avro definition
4. Catch AvroRuntimeException at construction and surface a clear validation error to the caller

Example fix

// before
GenericSchemaImpl.of(badSchemaInfo); // AvroRuntimeException
// after
if (SchemaType.AVRO.equals(badSchemaInfo.getType()) && isValidAvroRecordSchema(badSchemaInfo.getSchema())) {
    GenericSchemaImpl.of(badSchemaInfo);
} else {
    throw new IllegalArgumentException("SchemaInfo must contain a valid Avro RECORD schema");
}

Schema avroSchema = new Schema.Parser().setValidate(true).parse(new String(schemaInfo.getSchema(), StandardCharsets.UTF_8));
if (avroSchema.getType() != Schema.Type.RECORD) {
    throw new IllegalArgumentException("GenericSchemaImpl requires an Avro RECORD schema, got: " + avroSchema.getType());
}

boolean isAvroRecordSchema(SchemaInfo info) {
    try {
        return new Schema.Parser().parse(new String(info.getSchema(), StandardCharsets.UTF_8)).getType() == Schema.Type.RECORD;
    } catch (RuntimeException e) {
        return false;
    }
}

try {
    GenericSchemaImpl.of(schemaInfo);
} catch (AvroRuntimeException e) {
    log.error("Schema not usable as Avro generic record schema: {}", e.getMessage());
    throw new IllegalArgumentException("Provide a valid Avro RECORD schema", e);
}

When it happens

Trigger: Constructing GenericSchemaImpl (directly or via a subclass) with a Schema object whose getFields() raises AvroRuntimeException — e.g. a primitive-typed schema, malformed Avro schema, or a non-record schema passed where a record schema is required.

Common situations: Passing a primitive schema (STRING/INT) instead of a record schema; corrupt or hand-written SchemaInfo JSON that Avro cannot parse; programmatically constructed Avro schemas of unexpected type (ARRAY, MAP) fed to the generic record schema.

Related errors

• Avro Record Builder doesn't support non-avro record as a fie
• Generic schema is not supported on schema type <schemaInfo.g
• Can't get generic schema for topic <schemaInfoProvider.getTo
• Can not enable for all producers but denies for replicators,
• Failed to add schema to an active topic with empty(BYTES) sc

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/43ed75db8fb2876f. Report an issue: GitHub.