apache/cassandra · error · IllegalStateException

Invalid default spec:

Error message

Invalid default spec: 

What it means

OptionRatioDistribution is a cassandra-stress CLI option that defines a ratio between two quantities (e.g. column size vs count). When no user value was supplied, it falls back to a default spec string by parsing it with a fresh sub-option; this error means the default spec string failed to parse, so the option cannot produce any value.

Source

Thrown at tools/stress/src/org/apache/cassandra/stress/settings/OptionRatioDistribution.java:92

    }

    public static RatioDistributionFactory get(String spec)
    {
        OptionRatioDistribution opt = new OptionRatioDistribution("", "", "", true);
        if (!opt.accept(spec))
            throw new IllegalArgumentException("Invalid ratio definition: "+spec);
        return opt.get();
    }

    public RatioDistributionFactory get()
    {
        if (delegate.setByUser())
            return new DelegateFactory(delegate.get(), divisor);
        if (defaultSpec == null)
            return null;
        OptionRatioDistribution sub = new OptionRatioDistribution("", null, null, true);
        if (!sub.accept(defaultSpec))
            throw new IllegalStateException("Invalid default spec: " + defaultSpec);
        return sub.get();
    }

    @Override
    public boolean happy()
    {
        return delegate.happy();
    }

    public String longDisplay()
    {
        return delegate.longDisplay();
    }

    @Override
    public List<String> multiLineDisplay()
    {
        return Arrays.asList(

View on GitHub (pinned to 88fd0f6a0e)

Solutions

1. Fix the default spec string to be a valid ratio of the form '<number>/<number>', e.g. "1/4".
2. Print the offending spec (it is included in the exception message) and validate it against the ratio pattern before passing it in.
3. Pass the ratio explicitly on the command line so delegate.setByUser() is true and the default path is never taken.
4. If you don't need a default, pass null as defaultSpec so get() returns null instead of parsing.

Example fix

// before
OptionRatioDistribution opt = new OptionRatioDistribution("size", null, "one tenth", false);
// after
OptionRatioDistribution opt = new OptionRatioDistribution("size", null, "1/10", false);

if (defaultSpec != null && !defaultSpec.matches("\\d+(\.\\d+)?/\\d+(\.\\d+)?")) throw new IllegalArgumentException("bad ratio default: " + defaultSpec);

When it happens

Trigger: Calling get() (via apply()) on an OptionRatioDistribution where delegate.setByUser() is false, defaultSpec != null, and the internal sub-option's accept(defaultSpec) returns false — i.e. the hardcoded or programmatically passed default spec string does not match the expected '<dividend>/<divisor>' ratio format.

Common situations: A developer embedding cassandra-stress settings programmatically passes a malformed default like '1.5' or 'n/2' instead of a numeric ratio like '1/10'; a typo in a wrapper script that constructs the default spec; a refactoring changed the accepted pattern but not the default string.

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

• You need to state at least one --target host to replay the q
• Must specify at least one command with a non-zero ratio
• Must specify at least one command with a non-zero ratio
• Invalid data rate: value must be non-negative
• Invalid data storage: %s Accepted units:%s

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/5d2a38860e5cdcad. Report an issue: GitHub.