Luci statistics: shorter timespan?

Gigabit · December 13, 2020, 12:23pm

@hnyman And you see within five seconds, the graph updating if you start a download for example?

Gigabit · December 13, 2020, 12:29pm

@hnyman I followed your steps exactly and the graph is still delayed, I have 5 second refresh on and the data is almost a minute behind still.

hnyman · December 13, 2020, 12:49pm

Well, I have a well tailored SQM, so there is not much bump.

But there actually is a delay of 60 seconds. I didn't notice that angle in your first message, sorry.

LuCI statistics is usually meant for longer-term stats history, so the last few seconds have not been viewed that important for graphs.

In the graph system update in March, jow set it so that independently of the timespan, the last 60 seconds are not attempted to be shown, as there is a likelyhood that data for the last 30-60 seconds may be missing due to the default reporting interval.

github.com

openwrt/luci/blob/master/applications/luci-app-statistics/htdocs/luci-static/resources/statistics/rrdtool.js#L337


      
          	},
          
          	_forcelol: function(list) {
          		return L.isObject(list[0]) ? list : [ list ];
          	},
          
          	_rrdtool: function(def, rrd, timespan, width, height, cache) {
          		var cmdline = [
          			'graph', '-', '-a', 'PNG',
          			'-s', 'NOW-%s'.format(timespan || this.opts.timespan),
          			'-e', 'NOW-15',
          			'-w', width || this.opts.width,
          			'-h', height || this.opts.height
          		];
          
          		for (var i = 0; i < def.length; i++) {
          			var opt = String(def[i]);
          
          			if (rrd)
          				opt = opt.replace(/\{file\}/g, rrd);

You could patch that away in your own router, so that it would try to display until the last seconds.
That is /www/luci-static/resources/statistics/rrdtool.js in a live router.

Reference to discussion in https://github.com/openwrt/luci/issues/4065#issuecomment-629834609

Gigabit · December 13, 2020, 1:34pm

Hi @hnyman,

I edited the js file and removed the -e line and sadly it has not made much difference

I cleared /tmp/rrd again and restarted all the services.

hnyman · December 13, 2020, 1:37pm

Did you also refresh the luci cache ( /tmp/luci* ), restart uhttpd and clear the browser's cache...
The javascript changes are sometimes hard to get to applied.

I usually
rm -rf /tmp/luci*
/etc/init.d/uhttpd restart
(and clear/refresh brower page )

hnyman · December 13, 2020, 1:38pm

That '-e' (= endpoint) should actually be edited to be just

'-e', 'NOW',

so that the -60 gets removed

Gigabit · December 13, 2020, 1:59pm

Wahey @hnyman that's done it, now within a few seconds of the live data! Amazing you're a hero!

Gigabit · December 13, 2020, 2:06pm

@hnyman I guess one more question, is it possible to add auto-refresh of once a second?

hnyman · December 13, 2020, 2:15pm

I have never tried it. but the 5/30/60 in the selection are defined somewhere in the source code. Just add 1 sec there as an option, and modify the needed bits if it needs further changes.

But that might tax your router's CPU a bit, so depending on your CPU power vs. internet bandwidth, you might see negative effects.

EDIT:

github.com

openwrt/luci/blob/4843841fda1e33eaf727c9626e2e8918fd5ee6ae/applications/luci-app-statistics/htdocs/luci-static/resources/view/statistics/graphs.js#L194


				'selected': (rrdtool.opts.host == host) ? 'selected' : null
			}, [ host ])
		}));
		var spanSel = E('select', { 'style': 'max-width:170px', 'data-name': 'timespan' }, L.toArray(uci.get('luci_statistics', 'collectd_rrdtool', 'RRATimespans')).map(function(span) {
			return E('option', {
				'selected': (rrdtool.opts.timespan == span) ? 'selected' : null
			}, [ span ])
		}));
		var timeSel = E('select', { 'style': 'max-width:170px', 'data-name': 'refresh' }, [
			E('option', { 'value': 0 }, [ _('Do not refresh') ]),
			E('option', { 'value': 5 }, [ _('Every 5 seconds') ]),
			E('option', { 'value': 30 }, [ _('Every 30 seconds') ]),
			E('option', { 'value': 60 }, [ _('Every minute') ])
		]);
		var graphDiv = E('div', { 'data-name': 'graphs' });
		var view = E([], [
			E('h2', {}, [ _('Statistics') ]),

hnyman · December 18, 2020, 4:08pm

Just documenting here, that I shortened the default endpoint delay in master from 60s to 15s with

github.com/openwrt/luci

luci-app-statistics: shorten delay at graph endpoint to 15s

committed 03:41PM - 18 Dec 20 UTC

hnyman

+1 -1

Shorten the visible delay at the statistics graph endpoint from 60 seconds to 15… seconds. The 60s delay was recently added as a way to remove a possible visible gap at the end of the hourly graph due to absence of recent data. Default data collection interval is 30s, so that 60s guarantees that there is data upto to the end of the graph. However, that 60s makes any recent activity to get displayed really slowly, after a 60-89 second delay. Shortening the gap to 15s, half of the default data collection period, should balance things: * Half of the time there may be a really narrow gap visible and half of the time there is no gap at all. * The most recent displayed data point is from 15-44 seconds ago (instead of 60-89 seconds ago). Neither 15 or 60 seconds makes any impact to the longer graphs. To accommodate to possibly shorter timespans, and to avoid the occasional wrong data series selected for longer period graphs (see #4065) the endpoint delay might be relative to the timespan. Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>