t8y2/dbx · error · IllegalArgumentException

Unknown method: " + method

Error message

Unknown method: " + method

What it means

KafkaAgent.dispatch routes an RPC method name to a handler via a switch over known mq_* methods. If the requested method is not one of the implemented operations, the default branch throws IllegalArgumentException listing the unknown method name.

Solutions

1. Use one of the supported method names exactly as defined in the dispatch switch (snake_case, mq_ prefix)
2. Check the agent version — if the method exists in a newer release, upgrade the deployed agent
3. Log/inspect the method value being sent; validate the method list client-side against the agent's supported operations

Example fix

// before
agent.result(Map.of("method", "mq_listTopicAcls", "params", ...));
// after
agent.result(Map.of("method", "mq_list_acls", "params", ...));

Set<String> supported = Set.of("mq_list_acls","mq_create_acls","mq_delete_acls","mq_describe_cluster","mq_get_consumer_lag" /* ... */);
if (!supported.contains(method)) throw new IllegalArgumentException("unsupported method: " + method);

try {
    return agent.result(params);
} catch (IllegalArgumentException e) {
    if (e.getMessage().startsWith("Unknown method:")) {
        // surface allowed method list to the caller
    }
    throw e;
}

When it happens

Trigger: Invoking the agent's result()/dispatch() with a method string that is not in the supported mq_* set (typo, unsupported op, method from a newer client against an older agent).

Common situations: Typo like 'mq_listAcls' vs 'mq_list_acls'; client and agent version skew (new mq_* method not present in deployed agent); dynamically built method names from config.

Related errors

• agent exited before
• agent exited before
• agent request panic
• agent response unavailable
• Agent runtime thread limits must be positive

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/2d53fc296ea61095. Report an issue: GitHub.

Appendix: source

Thrown at agents/drivers/kafka/src/main/java/com/dbx/agent/kafka/KafkaAgent.java:164

            case "mq_alter_topic_config" -> alterTopicConfig(params);
            // Consumer groups
            case "mq_list_consumer_groups" -> listConsumerGroups(params);
            case "mq_get_consumer_group_snapshot" -> getConsumerGroupSnapshot(params);
            case "mq_describe_consumer_group" -> describeConsumerGroup(params);
            case "mq_delete_consumer_group" -> deleteConsumerGroup(params);
            case "mq_reset_consumer_group_offsets" -> resetConsumerGroupOffsets(params);
            case "mq_list_producers" -> listProducers(params);
            // Messages
            case "mq_peek_messages" -> peekMessages(params);
            case "mq_send_message" -> sendMessage(params);
            // ACLs
            case "mq_list_acls" -> listAcls(params);
            case "mq_create_acls" -> createAcls(params);
            case "mq_delete_acls" -> deleteAcls(params);
            // Cluster / monitoring
            case "mq_describe_cluster" -> describeCluster(params);
            case "mq_get_consumer_lag" -> getConsumerLag(params);
            default -> throw new IllegalArgumentException("Unknown method: " + method);
        };
    }

    // -----------------------------------------------------------------------
    // Lifecycle
    // -----------------------------------------------------------------------

    private static Object handshakeResult() {
        return new HandshakeResult(1, 1, CAPABILITIES);
    }

    private static Object connect(JsonObject params) throws Exception {
        JsonObject conn = resolveBrokerConnection(connectionObject(params));
        Map<String, String> previousKerberosSystemProperties = applyKerberosSystemProperties(conn);
        AdminClient nextAdmin = null;
        KafkaProducer<String, byte[]> nextProducer = null;
        try {
            nextAdmin = buildAdminClient(conn);

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