apache/pulsar · error · SchemaSerializationException

Size of data received by BooleanSchema is not 1

Error message

Size of data received by BooleanSchema is not 1

What it means

BooleanSchema encodes booleans as exactly one byte. validate() rejects any payload whose length differs from 1 with SchemaSerializationException, so decoding/validating a message of the wrong size fails fast instead of producing garbage values.

Source

Thrown at pulsar-client/src/main/java/org/apache/pulsar/client/impl/schema/BooleanSchema.java:49

    private static final BooleanSchema INSTANCE;
    private static final SchemaInfo SCHEMA_INFO;

    static {
        SCHEMA_INFO = SchemaInfoImpl.builder()
                .name("Boolean")
                .type(SchemaType.BOOLEAN)
                .schema(new byte[0]).build();
        INSTANCE = new BooleanSchema();
    }

    public static BooleanSchema of() {
        return INSTANCE;
    }

    @Override
    public void validate(byte[] message) {
        if (message.length != 1) {
            throw new SchemaSerializationException("Size of data received by BooleanSchema is not 1");
        }
    }

    @Override
    public byte[] encode(Boolean message) {
        if (null == message) {
            return null;
        } else {
            return new byte[]{(byte) (message ? 1 : 0)};
        }
    }

    @Override
    public Boolean decode(byte[] bytes) {
        if (null == bytes) {
            return null;
        }
        validate(bytes);

View on GitHub (pinned to 820761864e)

Solutions

1. Ensure producers use Schema.BOOLEAN so values are encoded as exactly 1 byte
2. Check the payload length is 1 before calling validate/decode
3. Verify the topic's schema matches what producers actually publish (use broker schema validation enforce).

Example fix

// before
booleanSchema.validate(payload); // throws if payload.length != 1
// after
if (payload != null && payload.length == 1) {
    booleanSchema.validate(payload);
}

if (message == null || message.length != 1) {
    throw new IllegalArgumentException("Boolean payload must be exactly 1 byte");
}

boolean isValidBooleanPayload(byte[] msg) {
    return msg != null && msg.length == 1;
}

try {
    schema.validate(message);
} catch (SchemaSerializationException e) {
    log.warn("Skipping malformed boolean payload of length {}", message == null ? -1 : message.length);
}

When it happens

Trigger: Passing a byte[] of length 0 or >1 into Schema.BOOLEAN().validate(...) or a corrupted/wrongly-encoded payload into the decode path of a BOOLEAN schema topic.

Common situations: Publishing to a boolean-schema topic with a mismatched schema (e.g. sending strings or multi-byte data); hand-crafted payloads in tests or bridges from other systems producing non-1-byte booleans.

Related errors

• Size of data received by ByteSchema is not 1
• Size of data received by DoubleSchema is not 8
• Can not enable for all producers but denies for replicators,
• This method is not supported
• Can't get accurate schema information for topic ${topicName}

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/d7f4e663713ee519. Report an issue: GitHub.