apache/cassandra · error · java.lang.IllegalArgumentException

Threshold value for gc_warn_threshold

Error message

Threshold value for gc_warn_threshold (%d) must be greater than gc_log_threshold which is currently %d

What it means

setGCWarnThreshold enforces that gc_warn_threshold is strictly greater than the current gc_log_threshold whenever the warn threshold is non-zero. Setting it equal to or below gc_log_threshold is rejected because the warn threshold must fire before the log threshold.

Solutions

1. Raise gc_warn_threshold so it is strictly greater than getGCLogThreshold()
2. Lower gc_log_threshold first via setGCLogThreshold before setting the warn threshold
3. Set gc_warn_threshold to 0 to disable it
4. Reorder calls: set the log threshold after the warn threshold

Example fix

// before
DatabaseDescriptor.setGCLogThreshold(20000);
DatabaseDescriptor.setGCWarnThreshold(10000); // throws
// after
DatabaseDescriptor.setGCWarnThreshold(30000);
DatabaseDescriptor.setGCLogThreshold(20000);

if (warnMs != 0 && warnMs <= DatabaseDescriptor.getGCLogThreshold()) throw new IllegalArgumentException("gc_warn_threshold must exceed gc_log_threshold");

try { DatabaseDescriptor.setGCWarnThreshold(warn); } catch (IllegalArgumentException e) { logger.error("gc threshold ordering violated: {}", e.getMessage()); }

When it happens

Trigger: Calling setGCWarnThreshold(threshold) where threshold != 0 and threshold <= DatabaseDescriptor.getGCLogThreshold(); e.g. setting warn=10000ms while gc_log_threshold is 20000ms.

Common situations: Editing cassandra.yaml so gc_warn_threshold ends up lower than gc_log_threshold, or updating one threshold programmatically without reordering both.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

• Threshold value for gc_concurrent_phase_log_threshold
• Threshold value for gc_concurrent_phase_warn_threshold
• Threshold must be greater than 0
• Threshold must be less than Integer.MAX_VALUE
• Threshold value for gc_concurrent_phase_warn_threshold must…

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/b4b8a66572f76f12. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/config/DatabaseDescriptor.java:5048

    }

    public static long getGCWarnThreshold()
    {
        return conf.gc_warn_threshold.toMilliseconds();
    }

    public static void setGCWarnThreshold(long threshold)
    {
        if (threshold < 0)
            throw new IllegalArgumentException("Threshold value for gc_warn_threshold must be greater than or equal to 0");

        if (threshold > Integer.MAX_VALUE)
            throw new IllegalArgumentException("Threshold must be less than Integer.MAX_VALUE");

        long gcLogThresholdInMs = getGCLogThreshold();
        if (threshold != 0 && threshold <= gcLogThresholdInMs)
            throw new IllegalArgumentException("Threshold value for gc_warn_threshold (" + threshold + ") must be greater than gc_log_threshold which is currently "
                                               + gcLogThresholdInMs);

        conf.gc_warn_threshold = new DurationSpec.IntMillisecondsBound(threshold);
    }

    public static int getGCConcurrentPhaseLogThreshold()
    {
        return conf.gc_concurrent_phase_log_threshold.toMilliseconds();
    }

    public static void setGCConcurrentPhaseLogThreshold(int threshold)
    {
        if (threshold <= 0)
            throw new IllegalArgumentException("Threshold must be greater than 0");

        long gcConcurrentPhaseWarnThresholdInMs = getGCConcurrentPhaseWarnThreshold();
        if (gcConcurrentPhaseWarnThresholdInMs != 0 && threshold > gcConcurrentPhaseWarnThresholdInMs)
            throw new IllegalArgumentException("Threshold value for gc_concurrent_phase_log_threshold (" + threshold + ") must be less than gc_concurrent_phase_warn_threshold which is currently "

View on GitHub (pinned to 88fd0f6a0e)