apache/cassandra · error · IllegalArgumentException

Invalid duration. The

Error message

Invalid duration. The %s are specified multiple times

What it means

Thrown by Duration.Builder.validateOrder when the same duration unit appears more than once in a single duration literal. The builder tracks the index of the last unit parsed; if the next unit has the same index, the units are duplicated. Duration syntax requires each unit to appear at most once.

Solutions

1. Remove the duplicate unit and merge its values (e.g. '1d 2d' -> '3d')
2. Pre-validate the duration string with a regex ensuring each unit appears at most once before calling Duration.from
3. Catch IllegalArgumentException and report which unit was duplicated to the user

Example fix

// before
Duration.from("1y 6mo 1y")
// after
Duration.from("2y 6mo")

static boolean hasDuplicateUnits(String dur) {
  java.util.regex.Matcher m = java.util.regex.Pattern.compile("(y|mo|w|d|h|m|s|ms|us|ns)").matcher(dur);
  java.util.Set<String> seen = new java.util.HashSet<>();
  while (m.find()) { if (!seen.add(m.group())) return true; }
  return false;
}

try { Duration d = Duration.from(input); } catch (IllegalArgumentException e) { throw new IllegalArgumentException("Malformed duration (duplicate/out-of-order units): " + input, e); }

When it happens

Trigger: Parsing strings like Duration.from("1d 2d") or "1mo 2mo 3d" — any duration where a unit symbol is repeated in one literal passed to Duration.from or a duration column insert.

Common situations: Programmatically building duration strings by concatenating components without deduplicating units; user input like '2 years 6 months 1 year'; template bugs that append the same unit twice.

Understand the failure class

Background: "invalid duration" / "failed to parse duration": why your timeout, interval, or TTL string is rejected and which formats each library accepts — this error's family across 32 libraries.

Related errors

• Invalid duration. The
• Unable to convert ' ' to a duration
• Unknown duration symbol
• A CQL blob string must have an even length (since one byte…
• All values must be either negative or positive, got

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/6e089bce5c41bb6b. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/cql3/functions/types/Duration.java:600

         */
        private void validate(long units, long limit, String unitName)
        {
            checkArgument(
            units <= limit,
            "Invalid duration. The total number of %s must be less or equal to %s",
            unitName,
            Integer.MAX_VALUE);
        }

        /**
         * Validates that the duration values are added in the proper order.
         *
         * @param unitIndex the unit index (e.g. years=1, months=2, ...)
         */
        private void validateOrder(int unitIndex)
        {
            if (unitIndex == currentUnitIndex)
                throw new IllegalArgumentException(
                String.format(
                "Invalid duration. The %s are specified multiple times", getUnitName(unitIndex)));

            if (unitIndex <= currentUnitIndex)
                throw new IllegalArgumentException(
                String.format(
                "Invalid duration. The %s should be after %s",
                getUnitName(currentUnitIndex), getUnitName(unitIndex)));

            currentUnitIndex = unitIndex;
        }

        /**
         * Returns the name of the unit corresponding to the specified index.
         *
         * @param unitIndex the unit index
         * @return the name of the unit corresponding to the specified index.
         */

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