Error Is Not Exception: Micrometer's Silent CPU Metric on Native Image

Mon, 22 Jun 2026 00:00:00 +0000

Part 13 in the Memory Benchmark series.

The catch block that catches nothing

This code has a bug. Not a typo, not a logic error. A type hierarchy bug.

private double invoke(@Nullable Method method) {
    try {
        return method != null
            ? toDouble((Number) method.invoke(operatingSystemBean))
            : Double.NaN;
    }
    catch (IllegalAccessException | IllegalArgumentException
           | InvocationTargetException e) {
        return Double.NaN;
    }
}

That’s micrometer’s ProcessorMetrics.invoke() (v1.16.5). It calls JMX methods via reflection, wraps the call in three catch clauses. Standard defensive coding.

Micrometer on tsvinc

Error Is Not Exception: Micrometer's Silent CPU Metric on Native Image

The catch block that catches nothing