apache/seatunnel · error · SeaTunnelException

The value of Metric does not support ${metricType} data type

Error message

The value of Metric does not support ${metricType} data type

What it means

SeaTunnelMetricsContext.provideDynamicMetrics converts SeaTunnel Metric values into Hazelcast/Micrometer probes. It handles Counter and Meter; any other Metric implementation hits the else branch and throws SeaTunnelException 'The value of Metric does not support <SimpleName> data type'. This happens while serving dynamic metrics for the cluster/web UI.

Source

Thrown at seatunnel-engine/seatunnel-engine-server/src/main/java/org/apache/seatunnel/engine/server/metrics/SeaTunnelMetricsContext.java:56

    public void provideDynamicMetrics(MetricDescriptor tagger, MetricsCollectionContext context) {
        metrics.forEach(
                (name, metric) -> {
                    if (metric instanceof Counter) {
                        context.collect(
                                tagger.copy(),
                                name,
                                ProbeLevel.INFO,
                                toProbeUnit(metric.unit()),
                                ((Counter) metric).getCount());
                    } else if (metric instanceof Meter) {
                        context.collect(
                                tagger.copy(),
                                name,
                                ProbeLevel.INFO,
                                toProbeUnit(metric.unit()),
                                ((Meter) metric).getRate());
                    } else {
                        throw new SeaTunnelException(
                                "The value of Metric does not support "
                                        + metric.getClass().getSimpleName()
                                        + " data type");
                    }
                });
    }

    private ProbeUnit toProbeUnit(Unit unit) {
        return ProbeUnit.valueOf(unit.name());
    }
}

View on GitHub (pinned to cf67b549a7)

Solutions

1. Change the connector metric implementation to standard Counter or Meter from the engine API.
2. Rebuild the connector against the same SeaTunnel API version as the engine to avoid class identity mismatches.
3. Remove or disable the offending metric declaration in the connector.
4. Check the reported class SimpleName in the message to identify which plugin/metric is at fault.

Example fix

// before
return new Metric() { ... }; // custom implementation
// after
private final Counter rows = new CounterImpl();
public Counter getRows() { return rows; }

if (!(metric instanceof Counter) && !(metric instanceof Meter)) {
    throw new IllegalArgumentException("metric type not probeable: " + metric.getClass().getName());
}

static boolean isProbeableMetric(Object m) {
    return m instanceof Counter || m instanceof Meter;
}

try {
    metricsContext.provideDynamicMetrics(...);
} catch (SeaTunnelException e) {
    if (e.getMessage().startsWith("The value of Metric does not support")) {
        log.warn("unprobeable metric skipped: {}", e.getMessage());
    } else throw e;
}

When it happens

Trigger: A registered connector metric object's runtime class is neither Counter nor Meter (e.g. a custom Metric subclass or Gauge) when metrics are probed via provideDynamicMetrics, typically triggered by a metrics scrape or the SeaTunnel web UI.

Common situations: Custom connectors with custom Metric implementations; classpath mixing different metric API versions so an object that looks like a Counter is not java.util.function-type-matching; plugins compiled against a different SeaTunnel API version.

Related errors

• Unsupported metric class: ${metricClass}
• Unsupported convert %s to Map, typeDefine: %s
• Unsupported convert %s to Array, typeDefine: %s
• Unsupported convert ${value.getClass()} to Row, typeDefine:
• Unsupported convert ${value.getClass()} to byte[], typeDefin

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/7695a83561deae15. Report an issue: GitHub.