@Override
    public Map<String, Metric> getMetrics() {
        final Map<String, Metric> gauges = new HashMap<>();
        gauges.put("pool-size", (Gauge<Integer>) executor::getPoolSize);
        gauges.put("queued", (Gauge<Integer>) executor.getQueue()::size);
        gauges.put("active", (Gauge<Integer>) executor::getActiveCount);
        gauges.put("completed", (Gauge<Long>) executor::getCompletedTaskCount);
        return gauges;
    }
Return thread pool metrics
@return thread pool metrics map
jraft-core/src/main/java/com/alipay/sofa/jraft/util/ThreadPoolMetricSet.java