What causes "Unknown scaling policy: %s" in apache/shenyu?

Inspect the active scaling policy (scale/scaler config in admin DB or dashboard) and reset its id to 1, 2, or 3.

apache/shenyu · error · IllegalStateException

Unknown scaling policy

Error message

Unknown scaling policy: %s

What it means

ScaleService.executeScaling switches on the active scaling policy's id: "1" (manual/static), "2" and "3" (timed/dynamic tasks). Any other id throws IllegalStateException after stopping dynamic tasks, meaning the configured scaling policy id is not recognized by the scaler.

Solutions

Inspect the active scaling policy (scale/scaler config in admin DB or dashboard) and reset its id to 1, 2, or 3.
Re-create the scaling policy through the admin dashboard/API instead of manual DB edits.
Remove or disable the invalid policy row so the default branch (stopDynamicTask) path or a valid policy is selected.
Check for ShenYu version skew — policy ids must match what the running ScaleService supports.

Example fix

// before (invalid policy row)
INSERT INTO scale_policy (id, ...) VALUES ('custom-x', ...);
// after (supported ids only)
INSERT INTO scale_policy (id, ...) VALUES ('2', ...);

Defensive patterns

Strategy: validation

Validate before calling

Set<String> valid = Set.of("1", "2", "3");
if (!valid.contains(activePolicy.getId()))
    throw new IllegalStateException("policy id " + activePolicy.getId() + " is not a supported scaling policy");

Try / catch

try {
    scaleService.executeScaling();
} catch (IllegalStateException e) {
    LOG.error("scaling aborted: {}", e.getMessage()); // fall back to default policy
}

Prevention

Create scaling policies only through the admin dashboard/API
Never hand-edit the scale policy table
Validate policy id against {1,2,3} after DB restores or migrations

When it happens

Trigger: The active scaling policy record in the admin DB (scale policy table) has an id other than "1", "2" or "3" — e.g. a policy created by custom code, a corrupted row, or a version whose policy ids changed.

Common situations: Manually inserted/edited scale policy rows; restored DB data from another ShenYu version; plugin/extension creating policies with custom ids; leftover test data in the scaling policy table.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of apache/shenyu@567142e072 (2026-09-12). Data as JSON: /api/errors/e38ba492bb26032f. Report an issue: GitHub.

Appendix: source

Thrown at shenyu-admin/src/main/java/org/apache/shenyu/admin/scale/scaler/ScaleService.java:85

        ScalePolicyDO activePolicy = getActivePolicy();
        if (Objects.nonNull(activePolicy)) {
            switch (activePolicy.getId()) {
                case "1":
                    stopDynamicTask();
                    kubernetesScaler.scaleByNum(activePolicy.getNum());
                    break;
                case "2":
                    stopDynamicTask();
                    if (isWithinTimeRange(activePolicy)) {
                        kubernetesScaler.scaleByNum(activePolicy.getNum());
                    }
                    break;
                case "3":
                    startDynamicTask(scaleProperties.getMonitorInterval());
                    break;
                default:
                    stopDynamicTask();
                    throw new IllegalStateException("Unknown scaling policy: " + activePolicy.getId());
            }
        }
    }

    /**
     * get active policy.
     *
     * @return ScalePolicyDO
     */
    private ScalePolicyDO getActivePolicy() {
        return scalePolicyCache.getAllPolicies().stream()
                .filter(policy -> policy.getStatus() == 1)
                .min(Comparator.comparingInt(ScalePolicyDO::getSort))
                .orElseGet(() -> {
                    LOG.warn("No active scaling policy found.");
                    return null;
                });
    }

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