apache/skywalking · error · IllegalExpressionException

Unsupported bool operation.

Error message

Unsupported bool operation.

What it means

IllegalExpressionException at the bottom of BoolOp.boolOp's switch: the opType token reaching the scalar boolean AND/OR evaluator is neither MQEParser.AND nor MQEParser.OR. Grammar-level, && and || are the only boolean connectors, so a different token here means dispatch drift (a new connector token added to the grammar without a matching case here).

Source

Thrown at oap-server/mqe-rt/src/main/java/org/apache/skywalking/mqe/rt/operation/BoolOp.java:69

        }
        if (!checkBool(rightValue)) {
            throw new IllegalExpressionException("Bool Operation: The result of the right expression is not 1 or 0.");
        }
        switch (opType) {
            case MQEParser.AND:
                if (leftValue == 1 && rightValue == 1) {
                    return 1;
                } else {
                    return 0;
                }
            case MQEParser.OR:
                if (leftValue == 1 || rightValue == 1) {
                    return 1;
                } else {
                    return 0;
                }
            default:
                throw new IllegalExpressionException("Unsupported bool operation.");
        }
    }

    private static boolean checkExpression(ExpressionResult result) {
        return result.isBoolResult();
    }

    private static boolean checkBool(double v) {
        int i = (int) v;
        return i == 0 || i == 1;
    }
}

View on GitHub (pinned to 102af09b4a)

Solutions

1. Ensure parser (mqe-grammar) and runtime (mqe-rt) jars come from the same OAP build
2. If extending the grammar with a new boolean connector, add its case to this switch (AND/OR pattern)
3. Report upstream if reproduced with a stock expression on a clean install

catch (IllegalExpressionException e) { /* grammar/runtime skew — rebuild with matching mqe-grammar and mqe-rt */ }

When it happens

Trigger: Internal-only: a grammar/runtime version skew where the parser emits a boolean-connective token unknown to this switch, e.g. a fork adding 'xor' or an upgraded UI/parser against an older mqe-rt jar.

Common situations: Mixed-version OAP deployments; custom grammar extensions. Standard user queries with && and || never land on the default branch.

Related errors

• Bool Operation: The result of the left expression is not 1 o
• Bool Operation: The result of the right expression is not 1
• Unsupported predicted value type: {}
• Unsupported bool operation: {}
• Unsupported aggregateLabels function.

AI-assisted analysis of apache/skywalking@102af09b4a (2026-08-14). Data as JSON: /api/errors/b75cd464145237a6. Report an issue: GitHub.