alibaba/nacos · error · IllegalArgumentException

url can not be empty, url: {limitedUrl}

Error message

url can not be empty, url: {limitedUrl}

What it means

Thrown when entry is 'limitedUrlMap' and an entry's URL part (before ':') is empty. This happens when the value starts with ':' or has '::', e.g. ':200'. The URL string must be non-empty.

Source

Thrown at naming/src/main/java/com/alibaba/nacos/naming/misc/SwitchManager.java:256

                boolean sendBeatOnly = Boolean.parseBoolean(value);
                
                tempSwitchDomain.setSendBeatOnly(sendBeatOnly);
            }
            
            if (entry.equals(SwitchEntry.LIMITED_URL_MAP)) {
                Map<String, Integer> limitedUrlMap = new HashMap<>(16);
                
                if (!StringUtils.isEmpty(value)) {
                    String[] entries = value.split(",");
                    for (String each : entries) {
                        String[] parts = each.split(":");
                        if (parts.length < 2) {
                            throw new IllegalArgumentException("invalid input for limited urls");
                        }
                        
                        String limitedUrl = parts[0];
                        if (StringUtils.isEmpty(limitedUrl)) {
                            throw new IllegalArgumentException(
                                "url can not be empty, url: " + limitedUrl);
                        }
                        
                        int statusCode = Integer.parseInt(parts[1]);
                        if (statusCode <= 0) {
                            throw new IllegalArgumentException(
                                "illegal normal status code: " + statusCode);
                        }
                        
                        limitedUrlMap.put(limitedUrl, statusCode);
                        
                    }
                    
                    tempSwitchDomain.setLimitedUrlMap(limitedUrlMap);
                }
            }
            
            if (entry.equals(SwitchEntry.ENABLE_STANDALONE)) {

View on GitHub (pinned to 9b989acdf1)

Solutions

1. Ensure every URL segment before ':' is non-empty.
2. Remove stray commas or leading colons from the value.

Example fix

// before
PUT /v3/admin/ns/operator/switches?entry=limitedUrlMap&value=:200
// after
PUT /v3/admin/ns/operator/switches?entry=limitedUrlMap&value=/nacos:200

for (String entry : value.split(",")) {
    String[] parts = entry.split(":", 2);
    if (parts.length < 2 || parts[0].isEmpty()) {
        throw new IllegalArgumentException("URL part cannot be empty");
    }
}

function hasNoEmptyUrl(value: string): boolean {
  return value.split(',').every(e => {
    const idx = e.indexOf(':');
    return idx > 0;
  });
}

try {
  operatorV2Impl.updateSwitch("limitedUrlMap", value, debug);
} catch (NacosApiException e) {
  if (e.getMessage().contains("url can not be empty")) {
    value = value.replace(/(^|,),/g, '$1').replace(/^:/, '');
  }
}

When it happens

Trigger: PUT /v3/admin/ns/operator/switches with entry=limitedUrlMap and value where the URL segment is blank, e.g. value=':200', value='/ok:200,:500'.

Common situations: Leading/trailing commas producing empty URL parts, or typo like '::404'.

Related errors

• invalid input for limited urls
• illegal normal status code: {statusCode}
• distroThreshold can not be zero or negative: {threshold}
• illegal format, must be 'type:version', but got: {value}
• illegal version, must match: {UtilsAndCommons.VERSION_STRING

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/2cfabd874176f060. Report an issue: GitHub.