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
update[6] = current[6] > input ? current[6] : input;
                update[7] = current[7] > output ? current[7] : output;
                update[8] = current[8] > elapsed ? current[8] : elapsed;
                update[9] = current[9] > concurrent ? current[9] : concurrent;
            }
        } while (!reference.compareAndSet(current, update));
    }
    @Override
    public List<URL> lookup(URL query) {
        return monitorService.lookup(query);
    }
    @Override
    public URL getUrl() {
        return monitorInvoker.getUrl();
    }
    @Override
    public boolean isAvailable() {
        return monitorInvoker.isAvailable();
    }
    @Override
    public void destroy() {
        try {
            sendFuture.cancel(true);
        } catch (Throwable t) {
            logger.error("Unexpected error occur at cancel sender timer, cause: " + t.getMessage(), t);
        }
        monitorInvoker.destroy();
    }
}