alibaba/nacos · error · IllegalArgumentException

processors scale must between 0 and 1

Error message

processors scale must between 0 and 1

What it means

Thrown by EnvUtil.getAvailableProcessors(double scale) when the scale is outside [0, 1]. The method sizes pools as a fraction of available processors and rejects out-of-range fractions.

Source

Thrown at sys/src/main/java/com/alibaba/nacos/sys/env/EnvUtil.java:509

     */
    public static int getAvailableProcessors(int multiple) {
        if (multiple < 1) {
            throw new IllegalArgumentException("processors multiple must upper than 1");
        }
        Integer processor = getProperty(Constants.AVAILABLE_PROCESSORS_BASIC, Integer.class);
        return null != processor && processor > 0 ? processor * multiple
            : ThreadUtils.getSuitableThreadCount(multiple);
    }
    
    /**
     * Get a scale of available processor numbers from environment.
     *
     * @param scale scale from 0 to 1.
     * @return available processor numbers from environment, will not lower than 1.
     */
    public static int getAvailableProcessors(double scale) {
        if (scale < 0 || scale > 1) {
            throw new IllegalArgumentException("processors scale must between 0 and 1");
        }
        double result =
            getProperty(Constants.AVAILABLE_PROCESSORS_BASIC, int.class,
                ThreadUtils.getSuitableThreadCount(1))
                * scale;
        return result > 1 ? (int) result : 1;
    }
    
    public static DeploymentType getDeploymentType() {
        return deploymentType;
    }
    
    public static void setDeploymentType(DeploymentType deploymentType) {
        EnvUtil.deploymentType = deploymentType;
    }
}

View on GitHub (pinned to 9b989acdf1)

Solutions

1. Find the caller of getAvailableProcessors(double) and ensure scale is within [0, 1].
2. If the property is a percentage, divide by 100 before passing (e.g. 75 -> 0.75).
3. Clamp the value: Math.max(0.0, Math.min(1.0, scale)).
4. Correct the source configuration value.

Example fix

// before
// config: nacos.thread.pool.ratio=150 (intended as 150%)
double scale = 150.0;
int size = EnvUtil.getAvailableProcessors(scale); // throws

// after
double scale = 150.0 / 100.0; // 1.0, or clamp
int size = EnvUtil.getAvailableProcessors(Math.min(1.0, scale));

double scale = configuredScale; // from config
if (scale < 0 || scale > 1) {
    throw new IllegalArgumentException("thread scale must be in [0,1], got " + scale);
}
int size = EnvUtil.getAvailableProcessors(scale);

try {
    EnvUtil.getAvailableProcessors(scale);
} catch (IllegalArgumentException e) {
    // treat as percentage or clamp
    EnvUtil.getAvailableProcessors(Math.max(0.0, Math.min(1.0, scale)));
}

When it happens

Trigger: A caller passes a scale < 0 or > 1, usually from a misconfigured ratio property (e.g. 1.5 meaning '150%' or a negative value).

Common situations: A thread-pool ratio property set to >1 (user thinking percentage) or negative; a derived ratio computed incorrectly; configuration imported from another system with a different scale convention.

Related errors

• processors multiple must upper than 1
• Must be a file directory :
• nacos address
• serverList is empty,please check configuration
• 400

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/c5f4937b4a3dda3d. Report an issue: GitHub.