[rrd-developers] rrd file access code

[Tobias Oetiker]

Today Daniel.Pocock at barclayscapital.com wrote:

> To maximise the benefit of the striping algorithm, there is some
> additional code (which I'm yet to complete) which ensures that a newly
> created RRD will have it's first CDPs stored at the same offset within
> the RRD as the other stripes.  I'll try to generalise this concept to
> work within your new framework.  Do you see any problem with bumping the
> offset of a new RRD file in this way?

no sure what you mean by this ? you want to synchronize the RRA
pointers ? this is certanly possible. At the moment they actually
get randomized, so that not all RRDs flip to the next diskblock at
the same time ... :-) this reduces disk impact since whenever a new
block gets touched it has to be read into cache first ...

cheers
tobi

>
> The algorithm is aimed at products like Ganglia, where all the RRDs are
> the same size and updated at the same time.
>
> Regards,
>
> Daniel
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Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900