apache/cassandra · error · IllegalArgumentException

Unsupported type: + type

Error message

Unsupported type: + type

What it means

In PingRequest.get, the ConnectionType switch has no case for the given type (only URGENT/SMALL/LARGE are valid for pings), so the default branch throws. Note the message uses string concatenation '+ type' rather than formatting — a minor bug producing 'Unsupported type: + type' text. Reached via deserialize of a ping request with a corrupt/unsupported connection type.

Solutions

1. Upgrade the receiving node so it recognizes the new MessageCategory
2. If you added a category, add a case (and pool) for it in PingRequest.get()
3. Check cluster version alignment before pinging across versions

Example fix

// before
case SMALL_MESSAGES: return forSmall;
default: throw new IllegalArgumentException("Unsupported type: " + type);
// after
case SMALL_MESSAGES: return forSmall;
case NEW_CATEGORY: return forNew; // added for the new MessageCategory
default: throw new IllegalArgumentException("Unsupported type: " + type);

try { pool = PingRequest.get(category); } catch (IllegalArgumentException e) { log.warn("Unsupported ping category {}, dropping", category, e); /* drop ping */ }

When it happens

Trigger: Calling PingRequest.get(type) with a category outside URGENT_MESSAGES/SMALL_MESSAGES/LARGE_MESSAGES, e.g. from serializer.deserialize() when a future/new category is sent by a peer running a newer version.

Common situations: Rolling upgrades where a newer node sends a ping with a category the older node does not know; accidental addition of a new MessageCategory without updating this switch.

Related errors

• Invalid custom verb id + id + - we only allow custom ids…
• Invalid IP address ( . . . ) while deserializing inet…
• Invalid IP address while deserializing inet address
• Invalid verb id + id + - we only allow ids between 0 and…
• ParamType id must be non-negative (got + id + )

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/1994e179fd8dd0b2. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/net/PingRequest.java:56

    static final PingRequest forSmall  = new PingRequest(SMALL_MESSAGES);
    static final PingRequest forLarge  = new PingRequest(LARGE_MESSAGES);

    final ConnectionType connectionType;

    private PingRequest(ConnectionType connectionType)
    {
        this.connectionType = connectionType;
    }

    @VisibleForTesting
    public static PingRequest get(ConnectionType type)
    {
        switch (type)
        {
            case URGENT_MESSAGES: return forUrgent;
            case  SMALL_MESSAGES: return forSmall;
            case  LARGE_MESSAGES: return forLarge;
            default: throw new IllegalArgumentException("Unsupported type: " + type);
        }
    }

    static IVersionedSerializer<PingRequest> serializer = new IVersionedSerializer<PingRequest>()
    {
        public void serialize(PingRequest t, DataOutputPlus out, int version) throws IOException
        {
            out.writeByte(t.connectionType.id);
        }

        public PingRequest deserialize(DataInputPlus in, int version) throws IOException
        {
            return get(ConnectionType.fromId(in.readByte()));
        }

        public long serializedSize(PingRequest t, int version)
        {
            return 1;

View on GitHub (pinned to 88fd0f6a0e)