[rrd-users] VRULE Thickness and Legend Throttling

[Alex van den Bogaerdt]

>> 1) The single pixel thickness seems very hard to read, there is no
>> VRULE2 (like LINE2) type modifier.
>
> yes this is true, but I guess it would be pretty simple to change
> as all the code for handling LINE%f is already in place ...

This would be most useful if there's a requirement for more than one
different thickness.  But is there?

If not, maybe an option, e.g. --vrule-width 2, may be better?

Alternative:
merge hrule, vrule and line into a more generic solution.  The only thing
separating HRULE from LINE is the effect it has on autoscaling (correct?), a
modifier could prevent that. Another modifier could instruct LINE to take
its parameter as a timestamp instead of a rate.

LINE[width]:value[#color][:[legend][:STACK]][:dashes[=on_s[,off_s[,on_s,off_s]...]][:dash-offset=offset]][:style={optional|timestamp}[,{optional,timestamp}]...]

e.g.

LINE:1269169200#FF0000:huge:style=optional
LINE2:1269169200#FF0000:noon:style=timestamp
LINE2:3600#FF0000:one:STACK:style=timestamp

LINE2:1269169200#FF0000:noon:style=timestamp,optional
LINE2:86400#FF0000::STACK:style=timestamp,optional
LINE2:86400#FF0000::STACK:style=timestamp,optional
LINE2:86400#FF0000::STACK:style=timestamp,optional
LINE2:86400#FF0000::STACK:style=timestamp,optional


>> 2) Multiple Legend entries "Code Switch" "Code Switch" is rough, right
>> now I just show the last code switch to avoid it.
>
> if you have to mark many event, an additional graph element might
> be handy for placeing arrows with numbers into the graph and then
> listing out the legend either outside the graph or somehow
> appropriately inside the graph ... might be a bit more involved
> creating something like this ...

A different approach would be to export timestamps from rrdtool or from
rrdtool graph, and use those to create an overlay.

Needed would be:
* total width and height of image
* height and width of graph part of image
* timerange of entire graph part
* vertical range of graph part (not for this example, but it will follow
shortly, I'm sure)
* one or more points of intrest to be annotated, x, y (for vrule, hrule) or
both (for a point).

Then a separate program can handle all the annotations.

I think users should 'vote' for these:

VRULE{width}:...
or
--vrule-width {number}

and the rest should be discussed on rrd-developers (if intresting enough).

cheers,
Alex