alibaba/Sentinel · error · IllegalStateException

strArray() is unavailable if countAndSum() has been called

Error message

strArray() is unavailable if countAndSum() has been called

What it means

strArray(String... values) appends free-form string values to an entry and belongs to the string-array strategy. StatEntryFuncCountAndSum holds only two numeric AtomicLongs (count and value), has no storage for string values, and rejects the call with IllegalStateException.

Source

Thrown at sentinel-core/src/main/java/com/alibaba/csp/sentinel/eagleeye/StatEntryFunc.java:114

    @Override
    public void arraySet(long... values) {
        throw new IllegalStateException("arraySet() is unavailable if countAndSum() has been called");
    }

    @Override
    public void minMax(long candidate, String ref) {
        throw new IllegalStateException("minMax() is unavailable if countAndSum() has been called");
    }

    @Override
    public void batchAdd(long... values) {
        throw new IllegalStateException("batchAdd() is unavailable if countAndSum() has been called");
    }

    @Override
    public void strArray(String... values) {
        throw new IllegalStateException("strArray() is unavailable if countAndSum() has been called");
    }
}

class StatEntryFuncMinMax implements StatEntryFunc {

    private AtomicReference<ValueRef> max = new AtomicReference<ValueRef>(new ValueRef(Long.MIN_VALUE, null));
    private AtomicReference<ValueRef> min = new AtomicReference<ValueRef>(new ValueRef(Long.MAX_VALUE, null));

    @Override
    public void appendTo(StringBuilder appender, char delimiter) {
        ValueRef lmax = max.get();
        ValueRef lmin = min.get();

        appender.append(lmax.value).append(delimiter);
        if (lmax.ref != null) {
            appender.append(lmax.ref);
        }
        appender.append(delimiter);

View on GitHub (pinned to a3f40ba8e9)

Solutions

Use an entry configured for string values (strArray strategy) for label-style data.
Keep numeric metrics numeric: call countAndSum(1, numericValue).
If both are needed, create two entries in the same StatLogger with different key columns.

Example fix

// before
func.strArray("tagA", "tagB"); // count-and-sum entry -> throws

// after
// numeric entry
numFunc.countAndSum(1, value);
// separate string entry created for strArray
strFunc.strArray("tagA", "tagB");

Defensive patterns

Strategy: type-guard

Validate before calling

if (func.getStatType() == 2) {
    func.countAndSum(1, numericValue); // never strArray here
} else {
    func.strArray(labels);
}

Type guard

boolean isCountAndSum(StatEntryFunc f) { return f.getStatType() == 2; }

Prevention

Design metric schemas up front: numeric metrics never receive string values.
Use separate entries for labels vs numbers within the same StatLogger.
Centralize writes in typed recorder interfaces so string/numeric mistakes fail compilation.

When it happens

Trigger: Calling strArray(labels) on an entry bound to the count-and-sum func — e.g. a tag/label logging call routed to a numeric counter entry, or a dynamically typed reporting pipeline that assumes every entry accepts strings.

Common situations: Adding dimension labels to a numeric metric and reusing the same entry. A logging utility overloaded for strings and numbers forwards both styles to one entry. Metric schema evolution where a numeric metric later needs string annotations.

Related errors

AI-assisted analysis of alibaba/Sentinel@a3f40ba8e9 (2026-08-14). Data as JSON: /api/errors/b9be0dcb17da2efc. Report an issue: GitHub.