apache/cassandra · error · InvalidRequestException

In call to function %s, value 0x%s is not a valid binary rep

Error message

In call to function %s, value 0x%s is not a valid binary representation for type %s

What it means

Thrown by the blob conversion functions (BytesConversionFcts) when validating that a raw blob is a valid binary representation of the target type. If toType.validate throws MarshalException, the call is rejected with InvalidRequestException instead of returning garbage.

Source

Thrown at src/java/org/apache/cassandra/cql3/functions/BytesConversionFcts.java:120

                  toType.getType().udfType(),
                  BytesType.instance);
            this.toType = toType;
        }

        @Override
        public ByteBuffer execute(Arguments arguments)
        {
            ByteBuffer val = arguments.get(0);

            if (val != null)
            {
                try
                {
                    toType.getType().validate(val);
                }
                catch (MarshalException e)
                {
                    throw new InvalidRequestException(String.format("In call to function %s, value 0x%s is not a " +
                                                                    "valid binary representation for type %s",
                                                                    name, ByteBufferUtil.bytesToHex(val), toType));
                }
            }

            return val;
        }

        @Override
        public NativeFunction withLegacyName()
        {
            return new FromBlobFunction(toType, true);
        }
    }
}

View on GitHub (pinned to 88fd0f6a0e)

Solutions

Ensure the blob was produced by the matching *asblob function for the target type.
Check the hex literal length matches the type's serialized size (int=4 bytes, bigint=8, uuid=16).
If the type changed, migrate data via a correct re-serialization rather than a direct blob cast.

Example fix

// before: SELECT intastext(some_blob_col) ... where blob holds a 16-byte UUID
// after
SELECT uuidastext(some_blob_col) ... -- use the conversion matching the actual type

Defensive patterns

Strategy: validation

Validate before calling

// Java: verify size before conversion
// int blob must be 4 bytes, bigint 8, uuid 16
if (val.remaining() != 4) throw new IllegalArgumentException("expected 4-byte int blob");

Try / catch

catch (InvalidRequestException e) { if (e.getMessage().contains("not a valid binary representation")) { log.warn("blob/type mismatch"); } }

Prevention

Only feed blobs produced by the matching *asblob function.
Track the original type of blob columns in metadata.
Check serialized sizes per type before conversion.

When it happens

Trigger: Calling conversion functions like blobastext, textasblob, intasblob, or the generic blob-to-type function with bytes that fail the target type's validation (wrong byte count for fixed-size types, invalid encoding).

Common situations: Reinterpreting a blob produced for one type as another type (e.g. a 4-byte int blob passed where a UUID is expected); hand-crafted hex literals with wrong length; deserializing columns after a schema type change.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/a4ff8504f7029a89. Report an issue: GitHub.