apache/cassandra · error · ConfigurationException

MINIMUM_NAME_SIZE_CONFIG_OPTION has to be at least DEFAULT_M

Error message

MINIMUM_NAME_SIZE_CONFIG_OPTION has to be at least DEFAULT_MINIMUM_NAME_SIZE and at most MAXIMUM_NAME_SIZE

What it means

UUIDRoleNameGenerator.validateParameters() throws this ConfigurationException when the 'minimum_name_size' config option is outside the allowed range: below DEFAULT_MINIMUM_NAME_SIZE or above MAXIMUM_NAME_SIZE. It runs at generator construction/registration time, so a bad generator config prevents the role-name generator from being usable.

Source

Thrown at src/java/org/apache/cassandra/db/guardrails/UUIDRoleNameGenerator.java:119

        name = name.substring(0, size);
        name = enrich(NAME_PREFIX_KEY, name, options);
        name = enrich(NAME_SUFFIX_KEY, name, options);

        return name;
    }

    @Nonnull
    @Override
    public CustomGuardrailConfig getParameters()
    {
        return config;
    }

    @Override
    public void validateParameters() throws ConfigurationException
    {
        if (minimumNameSize < DEFAULT_MINIMUM_NAME_SIZE || minimumNameSize > MAXIMUM_NAME_SIZE)
            throw new ConfigurationException(MINIMUM_NAME_SIZE_CONFIG_OPTION + " has to be at least " + DEFAULT_MINIMUM_NAME_SIZE + " and at most " + MAXIMUM_NAME_SIZE);
    }

    private String enrich(String key, String generatedValue, Map<String, Object> options)
    {
        if (options == null || options.isEmpty())
            return generatedValue;

        if (options.containsKey(key))
        {
            Object value = options.get(key);

            if (value == null)
                throw new IllegalArgumentException("Value of " + key + " cannot be null.");

            if (!(value instanceof String))
                throw new IllegalArgumentException("Value of " + key + " is not a string.");

            if (NAME_PREFIX_KEY.equals(key))

View on GitHub (pinned to 88fd0f6a0e)

Solutions

Set minimum_name_size between DEFAULT_MINIMUM_NAME_SIZE and MAXIMUM_NAME_SIZE (36)
Read the message numbers: first value is the lower bound, second the upper bound; clamp your config into that range
If you want short names, use the smallest allowed minimum rather than 0

Example fix

// before
minimum_name_size: 0
// after
minimum_name_size: 4

Defensive patterns

Strategy: validation

Validate before calling

void checkMin(int minimumNameSize) {
    if (minimumNameSize < DEFAULT_MINIMUM_NAME_SIZE || minimumNameSize > MAXIMUM_NAME_SIZE)
        throw new IllegalArgumentException("minimum_name_size must be in [" + DEFAULT_MINIMUM_NAME_SIZE + "," + MAXIMUM_NAME_SIZE + "]");
}

Try / catch

try {
    generator.validateParameters();
} catch (ConfigurationException e) {
    if (e.getMessage().startsWith("minimum_name_size")) {
        // clamp config value into [DEFAULT_MINIMUM_NAME_SIZE, 36] and recreate
    } else throw e;
}

Prevention

Clamp minimum_name_size into [DEFAULT_MINIMUM_NAME_SIZE, 36] in your config loader
Never use 0 or negative values to mean 'no minimum'
Document the valid range next to the config key

When it happens

Trigger: Configuring UUIDRoleNameGenerator with minimum_name_size smaller than the built-in default minimum or larger than MAXIMUM_NAME_SIZE (36 for a UUID string), then calling validateParameters during creation.

Common situations: Operators setting minimum_name_size=0 or negative values believing 0 means 'unconstrained', or typos like 360 instead of 36 when intending to cap name length.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/c3af631f1a13e784. Report an issue: GitHub.