apache/cassandra · error · IllegalArgumentException

Invalid parameter list for sequence distribution…

Error message

Invalid parameter list for sequence distribution (min==max): 

What it means

The sequence distribution additionally rejects degenerate ranges where min equals max, since a sequence between two identical values is meaningless (it is what the fixed distribution is for). This exact IllegalArgumentException is thrown for such specs.

Solutions

1. Use FIX(value) when you want a constant population/value
2. Give min and max distinct values: SEQ(1..1000)
3. Add a bounds check in scripts generating the spec: throw if min >= max.

Example fix

// before
-pop seq=SEQ(1000..1000)
// after
-pop seq=FIX(1000)

boolean isDegenerate(long min, long max){ return min == max; } // require min < max for SEQ

try { DistributionFactory f = seq.getFactory(params); } catch (IllegalArgumentException e) { return OptionDistribution.get("FIX(" + min + ")"); }

When it happens

Trigger: Calling getFactory for the sequence impl where parsed min and max are equal, e.g. SEQ(1000..1000).

Common situations: Programmatically generated ranges whose bounds collapse to one value (e.g. both computed from the same variable); copy/paste of the same number for both bounds.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Invalid parameter list for sequence distribution (min>max):
• arguments for -F are json, yaml, table only.
• Cannot specify tokens without keyspace.
• Invalid parameter list for fixed distribution:
• Invalid parameter list for sequence distribution:

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/07754204ca497315. Report an issue: GitHub.

Appendix: source

Thrown at tools/stress/src/org/apache/cassandra/stress/settings/OptionDistribution.java:390

        @Override
        public DistributionFactory getFactory(List<String> params)
        {
            if (params.size() != 1)
                throw new IllegalArgumentException("Invalid parameter list for sequence distribution: " + params);
            final long min;
            final long max;
            try
            {
                String[] bounds = params.get(0).split("\\.\\.+");
                min = parseLong(bounds[0]);
                max = parseLong(bounds[1]);
            } catch (Exception ignore)
            {
                throw new IllegalArgumentException("Invalid parameter list for sequence distribution: " + params);
            }
            if (min == max)
                throw new IllegalArgumentException("Invalid parameter list for sequence distribution (min==max): " + params);

            if (min > max)
                throw new IllegalArgumentException("Invalid parameter list for sequence distribution (min>max): " + params);

            return new SequenceFactory(min, max);

        }
    }


    private static final class InverseFactory implements DistributionFactory
    {
        final DistributionFactory wrapped;
        private InverseFactory(DistributionFactory wrapped)
        {
            this.wrapped = wrapped;
        }

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