apache/cassandra · error · ProtocolException

Snappy compression is not supported in protocol V5

Error message

Snappy compression is not supported in protocol V5

What it means

Starting with native protocol V5, Cassandra no longer allows Snappy compression; only lz4 is supported. If a client negotiates protocol V5 (or higher) and sends STARTUP with COMPRESSION=snappy, this ProtocolException is thrown and the connection is rejected.

Solutions

1. Switch the client driver's compression to lz4
2. Force the driver to use protocol V4 if Snappy must be kept (set protocol version explicitly in the driver config)
3. Upgrade driver settings to the recommended lz4 compression for Cassandra 4+

Example fix

// before (driver config)
compression: 'snappy'
// after
compression: 'lz4'

// Only set snappy when the cluster supports protocol V4
if (serverProtocolVersion < ProtocolVersion.V5) cluster.compression = 'snappy'; else cluster.compression = 'lz4';

catch (protocol errors on connect) and retry with lz4 compression

When it happens

Trigger: Client driver configured with snappy compression AND connecting with native protocol version >= V5 (default in recent drivers connecting to Cassandra 4+).

Common situations: Upgrading Cassandra to 4.x+ where V5 is the default protocol version while the driver still has legacy snappy compression configured; driver version pinned to V5+ against a snappy-configured client; mixed fleet where older nodes accepted snappy on V4 but newer ones reject it.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• This instance does not support Snappy compression
• Invalid uncompressed frame length
• Provided frame does not appear to be LZ4 compressed
• Provided frame does not appear to be Snappy compressed
• Unknown compression algorithm

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/27c995ee215e3e6c. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/transport/messages/StartupMessage.java:109

        {
            if (new CassandraVersion(cqlVersion).compareTo(new CassandraVersion("2.99.0")) < 0)
                throw new ProtocolException(String.format("CQL version %s is not supported by the binary protocol (supported version are >= 3.0.0)", cqlVersion));
        }
        catch (IllegalArgumentException e)
        {
            throw new ProtocolException(e.getMessage());
        }

        if (options.containsKey(COMPRESSION))
        {
            String compression = toLowerCaseLocalized(options.get(COMPRESSION));
            if (compression.equals("snappy"))
            {
                if (Compressor.SnappyCompressor.instance == null)
                    throw new ProtocolException("This instance does not support Snappy compression");

                if (getSource().header.version.isGreaterOrEqualTo(ProtocolVersion.V5))
                    throw new ProtocolException("Snappy compression is not supported in protocol V5");

                connection.setCompressor(Compressor.SnappyCompressor.instance);
            }
            else if (compression.equals("lz4"))
            {
                connection.setCompressor(Compressor.LZ4Compressor.instance);
            }
            else
            {
                throw new ProtocolException(String.format("Unknown compression algorithm: %s", compression));
            }
        }

        connection.setThrowOnOverload("1".equals(options.get(THROW_ON_OVERLOAD)));

        ClientState clientState = state.getClientState();
        clientState.setClientOptions(options);
        String driverName = options.get(DRIVER_NAME);

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