Re: [hobbit] Re: [feature request] trackmax for all parameters

[Gildas Le Nadan <gn1 (at) sanger.ac.uk>]

Hi,

> > > > The TRACKMAX feature is really interesting as the max values get 
> > > > "diluted" in the week/month/year views.
[...SNIP...]
> > However, there has also been some requests to increase the granularity 
> > of the stored data, e.g. to keep 7 days worth of 5-minute averages as 
> > opposed to the current 2 days. And likewise for the other RRA's.
> > So if we're going to add MAX/MIN tracking to the RRD-files, we might as
> > well do it at the same time that we change the granularity. The numbers 
> > I've been thinking of are to keep
> >   * 30 days of 5-minute averages
> >   * 90 days of 15-minute averages
> >   * 360 days on 1-hour averages
> >   * 1080 days of 3-hour averages
[...SNIP...]
> We also have to keep in mind that TRACKMAX (and TRACKMIN) is a
> per-statusname option, not a global setting.
>
> I can take some time next week to add these features into hobbit, if we
> agree on how to do it. I propose a setting in hobbitserver.cfg for RRAS
> like :
>
> # hobbitserver.cfg sample
> # standard setup -- fits most needs
> rra = "RRA:AVERAGE:0.5:1:576";
> rra = "$rra RRA:AVERAGE:0.5:6:576";
> rra = "$rra RRA:AVERAGE:0.5:24:576";
> rra = "$rra RRA:AVERAGE:0.5:288:576";
[...SNIP...]
> I (or anybody) can provide dump/restore tools along with hobbit, too.

I like this approach where one can set the values that fits for his 
particular setup. Some of us don't really need to keep 5 minutes average 
forever, but keeping the absolute maximum is mandatory, so the ability 
to tweek the value to the needs seems like a definite win.

Of course, adjusting the rra setup for existing rrd, as well as adding 
min/max value makes the dump/restore tools an absolute necessity.

There's probably some caveats concerning the dump/restore when it 
happens while hobbitd_rrd tries to update the values of the rrd being 
recreated, no? If so, maybe the dump/restore tool could be integrated in 
hobbitd_rdd or do_rrd or in the future "rrd distribution backend"?

Also, I think the setup syntax is a bit confusing, I would prefer either

rra1 = "RRA:AVERAGE:0.5:1:576";
rra2 = "RRA:AVERAGE:0.5:6:576";
rra3 = "RRA:AVERAGE:0.5:24:576";
rra4 = "RRA:AVERAGE:0.5:288:576";

or

rra = "RRA:AVERAGE:0.5:1:576 \
	RRA:AVERAGE:0.5:6:576 \
	RRA:AVERAGE:0.5:24:576 \
	RRA:AVERAGE:0.5:288:576";