alibaba/nacos · error · NacosException

400

400

Error message

gray rule parse failed: raw rule[%s] doesn't match pattern[%s].

What it means

Thrown by SingleTagMatchGrayRule.parse when the raw rule does not split into exactly 2 parts on '=' (keyValueArray.length != KEY_VALUE_ARRAY_LENGTH). Returns NacosException code 400 (INVALID_PARAM). Single-tag rules accept only 'key=value1,value2,value3' — no && or || operators.

Source

Thrown at config/src/main/java/com/alibaba/nacos/config/server/model/gray/singletag/SingleTagMatchGrayRule.java:64

    public SingleTagMatchGrayRule() {
        super();
    }
    
    public SingleTagMatchGrayRule(String rawGrayRuleExp, int priority) {
        super(rawGrayRuleExp, priority);
    }
    
    /**
     * parse rule, accept key=value1,value2,value3.
     *
     * @param rawRule raw rule
     */
    @Override
    protected void parse(String rawRule) throws NacosException {
        this.isPatternMatch(rawRule, EXPRESSION_PATTERN);
        String[] keyValueArray = rawRule.trim().split(EQUAL_PATTERN);
        if (keyValueArray.length != KEY_VALUE_ARRAY_LENGTH) {
            throw new NacosException(NacosException.INVALID_PARAM, String.format(
                "gray rule parse failed: raw rule[%s] doesn't match pattern[%s].",
                rawRule, KEY_PATTERN + EQUAL_PATTERN + VALUE_PATTERN));
        }
        isPatternMatch(keyValueArray[0].trim(), KEY_PATTERN);
        isPatternMatch(keyValueArray[1].trim(), VALUE_PATTERN);
        this.tagKey = keyValueArray[0].trim();
        this.tagValueSet = Arrays.stream(keyValueArray[1].trim().split(VALUE_SPLITER_PATTERN))
            .map(String::trim).filter(StringUtils::isNotBlank).collect(Collectors.toSet());
    }
    
    @Override
    public boolean match(Map<String, String> labels) {
        if (labels.containsKey(tagKey) && tagValueSet.contains(labels.get(tagKey))) {
            return true;
        }
        return false;
    }
    

View on GitHub (pinned to 9b989acdf1)

Solutions

1. For single-tag rules use exactly 'key=value' or 'key=v1,v2,v3' format with exactly one '='.
2. If you need AND/OR logic, use the multi-tag grayType instead.
3. Validate the expression has exactly one '=' before submitting.

Example fix

// before
grayRuleExp = "zone=us-east-1&&env=prod"  // operators not allowed in single-tag
// after (single-tag)
grayRuleExp = "zone=us-east-1"
// or switch grayType to multi-tag for AND/OR

// Single-tag rule: exactly one '=' no && or ||
String[] kv = rawRule.split("=", -1);
if (kv.length != 2 || rawRule.contains("&&") || rawRule.contains("||")) {
    throw new IllegalArgumentException("invalid single-tag rule: " + rawRule);
}

try { configApi.publishGray(form); }
catch (NacosException e) {
    if (e.getErrCode() == NacosException.INVALID_PARAM)
        { /* single-tag needs key=value only */ } else throw e;
}

When it happens

Trigger: Submitting a single-tag grayRuleExp with no '=' or multiple '=', or attempting to use multi-tag operators (&&, ||) in a single-tag rule context.

Common situations: Wrong grayType selected (single-tag vs multi-tag); expression with operators intended for multi-tag; malformed key=value.

Related errors

• 400
• 400
• 10000
• 20002
• INVALID_PARAM

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/668f52049dcf9f42. Report an issue: GitHub.