apache/pulsar · error · RuntimeException

No key schema info or value schema info : key = ${keySchema.

Error message

No key schema info or value schema info : key = ${keySchema.getSchemaInfo()}, value = ${valueSchema.getSchemaInfo()}

What it means

After decoding the KeyValueSchemaInfo from the topic schema, KeyValueSchemaImpl.configureSchemaInfo pushes the key/value SchemaInfo into the subschemas and then derives its own schemaInfo. If that derivation yields null, the key or value schema info was missing/invalid, so it throws a RuntimeException naming both schema infos.

Source

Thrown at pulsar-client/src/main/java/org/apache/pulsar/client/impl/schema/KeyValueSchemaImpl.java:304

    @Override
    public void configureSchemaInfo(String topicName,
                                    String componentName,
                                    SchemaInfo schemaInfo) {
        if (schemaInfo == null) {
            log.info().attr("topic", topicName)
                    .log("KeyValueSchema starting from null SchemaInfo."
                            + " This means that the topic still has"
                            + " not a schema");
            return;
        }
        KeyValue<SchemaInfo, SchemaInfo> kvSchemaInfo = KeyValueSchemaInfo.decodeKeyValueSchemaInfo(schemaInfo);
        keySchema.configureSchemaInfo(topicName, "key", kvSchemaInfo.getKey());
        valueSchema.configureSchemaInfo(topicName, "value", kvSchemaInfo.getValue());
        configureKeyValueSchemaInfo();

        if (null == this.schemaInfo) {
            throw new RuntimeException(
                "No key schema info or value schema info : key = " + keySchema.getSchemaInfo()
                    + ", value = " + valueSchema.getSchemaInfo());
        }
    }

    @Override
    public Schema<KeyValue<K, V>> clone() {
        return KeyValueSchemaImpl.of(keySchema.clone(), valueSchema.clone(), keyValueEncodingType);
    }

    private void buildKeyValueSchemaInfo() {
        this.schemaInfo = KeyValueSchemaInfo.encodeKeyValueSchemaInfo(
                keySchema, valueSchema, keyValueEncodingType
        );
    }

    private void configureKeyValueSchemaInfo() {
        buildKeyValueSchemaInfo();

View on GitHub (pinned to 820761864e)

Solutions

1. Inspect the topic's schema info (admin schemas get) and re-upload a well-formed KeyValue schema with non-null key and value SchemaInfo
2. Ensure both key and value schemas have valid SchemaType and properties when building KeyValueSchemaInfo.encodeKeyValueSchemaInfo
3. Upgrade/align the client version so KeyValueSchemaInfo encoding/decoding matches what the broker stored

Example fix

// before
SchemaInfo kvInfo = SchemaInfoImpl.builder().schema(KeyValueSchemaInfo.encodeKeyValueSchemaInfo(null, null)).build(); // null sub-schema infos
// after
SchemaInfo kvInfo = SchemaInfoImpl.builder().schema(KeyValueSchemaInfo.encodeKeyValueSchemaInfo(keySchemaInfo, valueSchemaInfo)).build();

KeyValue<SchemaInfo, SchemaInfo> kv = KeyValueSchemaInfo.decodeKeyValueSchemaInfo(schemaInfo);
if (kv == null || kv.getKey() == null || kv.getValue() == null) throw new IllegalStateException("KeyValue schema info missing key or value SchemaInfo");

try { schema.configureSchemaInfo(topic, "key_value", schemaInfo); } catch (RuntimeException e) { if (e.getMessage().startsWith("No key schema info or value schema info")) { reUploadSchema(topic); } else throw e; }

When it happens

Trigger: Calling configureSchemaInfo(topicName, schemaInfo) (via fetchSchemaIfNeeded) with a KeyValue SchemaInfo whose decoded key or value SchemaInfo is null or has a null/unknown type, so configureKeyValueSchemaInfo() cannot build a schemaInfo.

Common situations: A KeyValue schema uploaded with a malformed/empty key or value SchemaInfo; schema info lost when copying schema metadata between topics; client versions producing subtly different KeyValueSchemaInfo encodings.

Related errors

• AutoConsumeSchema is not supported with schemaId
• The schema is not a KeyValueSchema
• External schema cannot be used with other Pulsar struct sche
• This method cannot be used under this SEPARATED encoding typ
• Can't get accurate schema information for ${topicName} using

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/2774c741156f920a. Report an issue: GitHub.