It should be Debug level.
https://github.com/alibaba/dubbo/blob/23084275bf695f41b5f84d927c351e9b2b04a2be/dubbo-monitor/dubbo-monitor-default/src/main/java/com/alibaba/dubbo/monitor/dubbo/DubboMonitor.java#L77
Statistics statistics = new Statistics(url);
        AtomicReference<long[]> reference = statisticsMap.get(statistics);
        if (reference == null) {
            statisticsMap.putIfAbsent(statistics, new AtomicReference<long[]>());
            reference = statisticsMap.get(statistics);
        }
        
        long[] current;
        long[] update = new long[LENGTH];
        do {
            current = reference.get();
            if (current == null) {
                update[0] = success;
                update[1] = failure;
                update[2] = input;
                update[3] = output;
                update[4] = elapsed;
                update[5] = concurrent;
                update[6] = input;
                update[7] = output;
                update[8] = elapsed;
                update[9] = concurrent;
            } else {
                update[0] = current[0] + success;
                update[1] = current[1] + failure;
                update[2] = current[2] + input;
                update[3] = current[3] + output;
                update[4] = current[4] + elapsed;
                update[5] = (current[5] + concurrent) / 2;