apache/cassandra · error · java.lang.IllegalArgumentException

Value must be >= 0 and <= 1 for repair_disk_headroom_reject_

Error message

Value must be >= 0 and <= 1 for repair_disk_headroom_reject_ratio

What it means

setRepairDiskHeadroomRejectRatio validates that the repair disk headroom ratio is a fraction in [0.0, 1.0] before storing it. Values outside this range are not meaningful as a disk-usage rejection ratio, so the setter throws IllegalArgumentException.

Source

Thrown at src/java/org/apache/cassandra/config/DatabaseDescriptor.java:6501

    {
        return conf.accord.ephemeral_reads;
    }

    public static AutoRepairConfig getAutoRepairConfig()
    {
        return conf.auto_repair;
    }

    public static double getRepairDiskHeadroomRejectRatio()
    {
        return conf.repair_disk_headroom_reject_ratio;
    }

    public static void setRepairDiskHeadroomRejectRatio(double value)
    {
        if (value < 0.0 || value > 1.0)
        {
            throw new IllegalArgumentException("Value must be >= 0 and <= 1 for repair_disk_headroom_reject_ratio");
        }
        conf.repair_disk_headroom_reject_ratio = value;
    }

    @VisibleForTesting
    public static void setPartitioner(String name)
    {
        partitioner = FBUtilities.newPartitioner(name);
    }

    public static boolean getGossipQuarantineDisabled()
    {
        return conf.gossip_quarantine_disabled;
    }

    public static void setGossipQuarantineDisabled(boolean disabled)
    {
        conf.gossip_quarantine_disabled = disabled;

View on GitHub (pinned to 88fd0f6a0e)

Solutions

1. Pass a value between 0.0 and 1.0 inclusive (e.g. 0.2 for 20% headroom).
2. Convert percentage-style values by dividing by 100 before setting.
3. Correct repair_disk_headroom_reject_ratio in cassandra.yaml.

Example fix

// before
DatabaseDescriptor.setRepairDiskHeadroomRejectRatio(20);
// after
DatabaseDescriptor.setRepairDiskHeadroomRejectRatio(0.20);

if (ratio >= 0.0 && ratio <= 1.0) DatabaseDescriptor.setRepairDiskHeadroomRejectRatio(ratio);

boolean isValidHeadroomRatio(double r) { return r >= 0.0 && r <= 1.0; }

try { DatabaseDescriptor.setRepairDiskHeadroomRejectRatio(ratio); } catch (IllegalArgumentException e) { log.error("bad repair_disk_headroom_reject_ratio", e); }

When it happens

Trigger: Calling DatabaseDescriptor.setRepairDiskHeadroomRejectRatio with a double < 0.0 or > 1.0, e.g. 1.5 or -0.1, via code, JMX, or a misconfigured repair_disk_headroom_reject_ratio value.

Common situations: Operators entering the ratio as a percentage (e.g. 20 instead of 0.2); YAML values parsed as whole numbers; scripts computing the ratio incorrectly yielding negatives.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

• Cannot set repair_session_max_tree_depth to which is < 10, d
• Cannot set concurrent_validations greater than concurrent_co
• Invalid data rate: value must be non-negative
• Invalid data storage: %s Accepted units:%s
• repair_session_max_tree_depth should not be < 10, but was ${

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/cbc29a1ae622dcbf. Report an issue: GitHub.