prestodb/presto · error · IllegalArgumentException

splitCount must be >= 0, found:

Error message

splitCount must be >= 0, found: 

What it means

SplitWeight.rawValueForStandardSplitCount converts a count of standard-weight splits into a raw weight value using Math.multiplyExact. It throws IllegalArgumentException("splitCount must be >= 0, found: ...") when splitCount is negative.

Source

Thrown at presto-spi/src/main/java/com/facebook/presto/spi/SplitWeight.java:104

    public static SplitWeight standard()
    {
        return STANDARD_WEIGHT;
    }

    public static SplitWeight fromProportion(double weight)
    {
        if (weight <= 0 || !Double.isFinite(weight)) {
            throw new IllegalArgumentException("Invalid weight: " + weight);
        }
        // Must round up to avoid small weights rounding to 0
        return fromRawValue((long) Math.ceil(weight * UNIT_VALUE));
    }

    public static long rawValueForStandardSplitCount(int splitCount)
    {
        if (splitCount < 0) {
            throw new IllegalArgumentException("splitCount must be >= 0, found: " + splitCount);
        }
        return multiplyExact(splitCount, UNIT_VALUE);
    }

    public static <T> long rawValueSum(Collection<T> collection, Function<T, SplitWeight> getter)
    {
        long sum = 0;
        for (T item : collection) {
            long value = getter.apply(item).getRawValue();
            sum = addExact(sum, value);
        }
        return sum;
    }
}

View on GitHub (pinned to 55bb57d202)

Solutions

1. Fix the caller so split counts never go negative (use max(0, count))
2. Audit increment/decrement logic for double decrements or underflow
3. Note multiplyExact will also throw ArithmeticException on overflow, so validate the range of the count too

Example fix

// before
long raw = SplitWeight.rawValueForStandardSplitCount(delta);
// after
long raw = SplitWeight.rawValueForStandardSplitCount(Math.max(0, delta));

if (splitCount < 0) splitCount = 0;

When it happens

Trigger: Calling SplitWeight.rawValueForStandardSplitCount(-1) or any negative count, typically from bookkeeping code computing split counts that underflowed.

Common situations: Subtracting more splits than were added in a stats tracker; int underflow on large counters; passing a delta instead of an absolute count.

Related errors

• value must be > 0, found:
• Invalid weight:
• partitionHandle must be NOT_PARTITIONED
• Invalid NodeState value:
• SchemaTableName should have exactly 2 parts

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/a86b87a6355d2b6d. Report an issue: GitHub.