alibaba/arthas · warning · IllegalArgumentException

{optionName} must be greater than 0.

Error message

{optionName} must be greater than 0.

What it means

Thrown as IllegalArgumentException by parseTimeMillis when the parsed duration (Long.parseLong(text) * multiplier) is <= 0. The numeric body parses fine but the resulting millisecond value is non-positive (e.g. 0, negative). A strictly positive duration is required.

Source

Thrown at core/src/main/java/com/taobao/arthas/core/command/klass100/ClassLoaderMetaspaceCommand.java:476

            throw new IllegalArgumentException(optionName + " must not be blank.");
        }

        String text = value.trim().toLowerCase();
        long multiplier = 1;
        if (text.endsWith("ms")) {
            text = text.substring(0, text.length() - 2).trim();
        } else if (text.endsWith("s")) {
            text = text.substring(0, text.length() - 1).trim();
            multiplier = 1000;
        } else if (text.endsWith("m")) {
            text = text.substring(0, text.length() - 1).trim();
            multiplier = 60 * 1000;
        }

        try {
            long millis = Long.parseLong(text) * multiplier;
            if (millis <= 0) {
                throw new IllegalArgumentException(optionName + " must be greater than 0.");
            }
            return millis;
        } catch (NumberFormatException e) {
            throw new IllegalArgumentException(optionName + " is invalid: " + value);
        }
    }

    private void logMappingSummary(MappingSummary summary) {
        logger.debug("{} mapping summary, loadedClasses={}, candidateLoaders={}, emittedMappings={}, bootstrapClasses={}, arrayClasses={}, primitiveClasses={}, duplicateLoaderClasses={}",
                DIAG_LOG_PREFIX, summary.loadedClassCount, summary.candidateLoaderCount, summary.emittedMappingCount,
                summary.bootstrapClassCount, summary.arrayClassCount, summary.primitiveClassCount,
                summary.duplicateLoaderClassCount);
    }

    private void logRecordingSummary(RecordingData data, long recordingSize) {
        logger.debug("{} recording summary, fileSizeBytes={}, statsEvents={}, distinctStatsRows={}, mappingEvents={}, fallbackMappings={}, mappedLoaderIds={}, mappingEventsWithoutLoader={}, duplicateStatsRows={}",
                DIAG_LOG_PREFIX, recordingSize, data.statsEventCount, data.statsRows.size(), data.mappingEventCount,
                data.fallbackMappings.size(), data.mappingByLoaderId.size(), data.mappingEventWithoutLoaderCount,

View on GitHub (pinned to 21cf2e9ba5)

Solutions

1. Use a positive value: 1s, 500ms, 5m, etc.
2. If you mean 'no interval', omit the option (use its default) instead of passing 0.
3. Check for stray negative signs or zero defaults in config.

Example fix

// before
classloader --refresh-interval 0s

// after
classloader --refresh-interval 5s

long ms = parseMillisRaw(value);
if (ms <= 0) { // reject before calling; supply a positive duration }

static boolean isPositiveDuration(String s) {
    if (s == null) return false;
    try { return Long.parseLong(stripSuffix(s)) > 0; } catch (NumberFormatException e) { return false; }
}

try { long ms = parseTimeMillis(value, optionName); } catch (IllegalArgumentException e) { /* prompt user for a value > 0 */ }

When it happens

Trigger: Pass a time option value of '0', '0s', '0m', '0ms', or a negative number like '-5s'. The multiplier (1 for ms, 1000 for s, 60000 for m) is applied, and millis <= 0 trips the guard.

Common situations: User intends 'disable' and passes 0; copy-paste mistake with a leading minus; default-of-zero from a misconfigured config file.

Related errors

• {optionName} is invalid: {value}
• {optionName} must not be blank.
• '{s}' is not a valid size. Should be numeric value followed
• '{s}' is not a valid timespan. Shoule be numeric value follo
• The --line option is required unless --list-lines is used.

AI-assisted analysis of alibaba/arthas@21cf2e9ba5 (2026-08-14). Data as JSON: /api/errors/7838bc359c366485. Report an issue: GitHub.