What causes "Plugin config value is not a number: {key}" in alibaba/nacos?

Set the timeout to a plain integer in milliseconds (e.g. 3000), no units or separators.

alibaba/nacos · error · IllegalArgumentException

Plugin config value is not a number

Error message

Plugin config value is not a number: {key}

What it means

Thrown by LdapAuthPluginConfig.parsePositiveLong() when the timeout value cannot be parsed as a long at all (NumberFormatException). The original exception is chained as the cause. The error message names the 'timeout' key so the operator knows which value is malformed.

Solutions

Set the timeout to a plain integer in milliseconds (e.g. 3000), no units or separators.
If the value comes from an environment variable, ensure it is a clean numeric string.
Validate the timeout string with a regex like ^\d+$ before passing it into the config.

Example fix

# before
nacos.plugin.auth.ldap.timeout=3s

# after
nacos.plugin.auth.ldap.timeout=3000

Defensive patterns

Strategy: validation

Validate before calling

String timeoutStr = config.getOrDefault("timeout", "3000");
if (!timeoutStr.matches("^\\d+$")) {
    throw new IllegalArgumentException("timeout must be a plain integer");
}

Type guard

static boolean isPlainNumeric(String value) {
    return value != null && value.matches("^\\d+$");
}

Try / catch

try {
    LdapAuthPluginConfig parsed = LdapAuthPluginConfig.from(config);
} catch (IllegalArgumentException e) {
    // if message contains 'not a number', fix the timeout to a plain integer
}

Prevention

Use a bare integer (e.g. 3000) for timeout; no units, commas, or suffixes.
Validate numeric config values with a regex before parsing.
Document accepted config formats for operators.

When it happens

Trigger: LdapAuthPluginConfig.from() calls parsePositiveLong for the timeout key, but the value is a non-numeric string (e.g. "3s", "abc", "3,000"). Long.parseLong throws NumberFormatException, caught and rethrown as IllegalArgumentException.

Common situations: Operator enters a human-readable duration like "3s" or "3000ms" instead of a bare number; a locale-specific number format (comma thousands separator) is used; a stray character is pasted into the value.

Related errors

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/76601fac0febf47e. Report an issue: GitHub.

Appendix: source

Thrown at plugin-default-impl/nacos-ldap-auth-plugin/src/main/java/com/alibaba/nacos/plugin/auth/impl/ldap/LdapAuthPluginConfig.java:145

        if (config == null || !config.containsKey(key)) {
            return defaultValue;
        }
        String result = config.get(key);
        if (result == null) {
            throw new IllegalArgumentException("Plugin config value cannot be null: " + key);
        }
        return result;
    }
    
    private static long parsePositiveLong(String value, String key) {
        try {
            long result = Long.parseLong(value);
            if (result <= 0) {
                throw new IllegalArgumentException("Plugin config value must be positive: " + key);
            }
            return result;
        } catch (NumberFormatException e) {
            throw new IllegalArgumentException("Plugin config value is not a number: " + key, e);
        }
    }
    
    private static boolean parseBoolean(String value, String key) {
        if (!Boolean.TRUE.toString().equalsIgnoreCase(value)
            && !Boolean.FALSE.toString().equalsIgnoreCase(value)) {
            throw new IllegalArgumentException("Plugin config value is not a boolean: " + key);
        }
        return Boolean.parseBoolean(value);
    }
    
    public String getUrl() {
        return url;
    }
    
    public String getBaseDn() {
        return baseDn;
    }

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