alibaba/nacos · error · NacosApiException

PARAMETER_MISSING

PARAMETER_MISSING

Error message

Required parameter 'entry' type String is not present

What it means

Thrown by UpdateSwitchForm.validate() when the 'entry' field is blank in a server-switch update request. Nacos exposes runtime switches (e.g. defaultPushEmptyService, distroThreshold) addressable by a key; 'entry' names the switch to modify, so a blank entry yields HTTP 400 PARAMETER_MISSING.

Source

Thrown at naming/src/main/java/com/alibaba/nacos/naming/model/form/UpdateSwitchForm.java:52

    private static final long serialVersionUID = -1580959130954136990L;
    
    private boolean debug;
    
    private String entry;
    
    private String value;
    
    public UpdateSwitchForm() {
    }
    
    /**
     * check param.
     *
     * @throws NacosApiException NacosApiException
     */
    public void validate() throws NacosApiException {
        if (StringUtils.isBlank(entry)) {
            throw new NacosApiException(HttpStatus.BAD_REQUEST.value(), ErrorCode.PARAMETER_MISSING,
                "Required parameter 'entry' type String is not present");
        }
        if (StringUtils.isBlank(value)) {
            throw new NacosApiException(HttpStatus.BAD_REQUEST.value(), ErrorCode.PARAMETER_MISSING,
                "Required parameter 'value' type String is not present");
        }
    }
    
    public boolean getDebug() {
        return debug;
    }
    
    public void setDebug(boolean debug) {
        this.debug = debug;
    }
    
    public String getEntry() {
        return entry;

View on GitHub (pinned to 9b989acdf1)

Solutions

Provide a valid, non-blank 'entry' key (e.g. 'checkers', 'defaultPushEmptyService').
First query GET /operator/switches to enumerate available entry names and their current values.
Pre-validate StringUtils.isNotBlank(form.getEntry()).

Example fix

// before
curl -X PUT '.../operator/switches' -d 'value=true'
// after
curl -X PUT '.../operator/switches' -d 'entry=defaultPushEmptyService&value=true'

Defensive patterns

Strategy: validation

Validate before calling

if (StringUtils.isBlank(entry)) {
    throw new IllegalArgumentException("entry (switch key) is required");
}
form.setEntry(entry);
form.setValue(value);

Type guard

static boolean hasValidSwitchEntry(String e) {
    return e != null && !e.trim().isEmpty();
}

Prevention

List available switches via GET /operator/switches before updating.
Keep an enum/set of known entry names in your client config.
Pre-validate entry+value together.

When it happens

Trigger: PUT/POST to the switch update endpoint (e.g. /v3/admin/ns/operator/switches or legacy /nacos/v1/ns/operator/switches) with no 'entry'.

Common situations: Calling the switch API without knowing the available entry names; UI free-text field left empty; malformed automation that passes only 'value'.

Related errors

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/450aa5a92c9f89f6. Report an issue: GitHub.