apache/cassandra · critical · ConfigurationException

broadcast_rpc_address cannot be a wildcard address (

Error message

broadcast_rpc_address cannot be a wildcard address (

What it means

Cassandra refuses to start if broadcast_rpc_address resolves to the wildcard address 0.0.0.0 (or ::), because a wildcard address cannot be meaningfully advertised to client drivers as the node's RPC endpoint. The check runs after resolution in applyAddressConfig.

Solutions

  1. Set broadcast_rpc_address to the node's specific routable IP or resolvable hostname
  2. If clients connect directly and no NAT is involved, remove broadcast_rpc_address entirely and keep rpc_address: 0.0.0.0 for binding
  3. In Kubernetes/NAT setups use the address reachable by clients (pod IP, Service/NAT address)

Example fix

// cassandra.yaml before
rpc_address: 0.0.0.0
broadcast_rpc_address: 0.0.0.0
// after
rpc_address: 0.0.0.0
broadcast_rpc_address: 10.0.1.5
Defensive patterns

Strategy: validation

Validate before calling

String addr = config.broadcast_rpc_address;
if (addr != null) {
    java.net.InetAddress ia = java.net.InetAddress.getByName(addr);
    if (ia.isAnyLocalAddress()) throw new IllegalStateException("broadcast_rpc_address must not be wildcard: " + addr);
}

Try / catch

try { DatabaseDescriptor.daemonInitialization(); } catch (ConfigurationException e) { /* fix yaml, not retryable */ }

Prevention

When it happens

Trigger: Setting broadcast_rpc_address: 0.0.0.0 (or a hostname resolving to the wildcard) in cassandra.yaml and calling DatabaseDescriptor.loadConfig() during startup.

Common situations: Operator copies rpc_address's wildcard value into broadcast_rpc_address misunderstanding that broadcast must be a specific routable address; templated configs that blanket-substitute bind addresses.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/6ae2c557fc3307aa. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/config/DatabaseDescriptor.java:1582

        else
        {
            rpcAddress = FBUtilities.getJustLocalAddress();
        }

        /* RPC address to broadcast */
        if (config.broadcast_rpc_address != null)
        {
            try
            {
                broadcastRpcAddress = InetAddress.getByName(config.broadcast_rpc_address);
            }
            catch (UnknownHostException e)
            {
                throw new ConfigurationException("Unknown broadcast_rpc_address '" + config.broadcast_rpc_address + '\'', false);
            }

            if (broadcastRpcAddress.isAnyLocalAddress())
                throw new ConfigurationException("broadcast_rpc_address cannot be a wildcard address (" + config.broadcast_rpc_address + ")!", false);
        }
        else
        {
            if (rpcAddress.isAnyLocalAddress())
                throw new ConfigurationException("If rpc_address is set to a wildcard address (" + config.rpc_address + "), then " +
                                                 "you must set broadcast_rpc_address to a value other than " + config.rpc_address, false);
        }
    }

    public static void applyEncryptionContext()
    {
        // always attempt to load the cipher factory, as we could be in the situation where the user has disabled encryption,
        // but has existing commitlogs and sstables on disk that are still encrypted (and still need to be read)
        encryptionContext = new EncryptionContext(conf.transparent_data_encryption_options);
    }

    public static void applySslContext()
    {

View on GitHub (pinned to 88fd0f6a0e)