[rrd-users] rrdtool multi DS heartbeat problem

[Tobias Oetiker]

Hi Mike,

Yesterday Mike Schilli wrote:

> On Sun, 26 Apr 2009, Mike Schilli wrote:
>
> > With multiple data sources, there seems to be a bug with rrdtool,
> > causing it to ignore the heartbeat settings.
>
> Any resolution on this issue?

this is not a bug, but rather at the heart of rrdtools way of working.
Updates to an rrd with multiple datasources are always
'synchronous'. If you setup a template which does not
include all Datasources, the remaining datasources get the
aequivalent of an update with an 'U' value ...

> > Here's a test case that reproduces the problem: We define a rrd with two
> > data sources, each with a generous heartbeat of 57600:
> >
> >  rrdtool 'create' 'myrrdfile.rrd' '--start' '1240729199' \
> >  '--step' '3600' 'DS:d2:GAUGE:57600:U:U' \
> >  'DS:d1:GAUGE:57600:U:U' 'RRA:MAX:0.5:1:100'
> >
> > Then we feed in data, with separate calls for the data sources:
> >
> >  rrdtool 'update' 'myrrdfile.rrd' '--template' 'd1' '1240729200:100'

this is aquivalent to

 rrdtool 'update' 'myrrdfile.rrd' '--template' 'd1:d2' '1240729200:100:U'

> >  rrdtool 'update' 'myrrdfile.rrd' '--template' 'd2' '1240729201:100'

 rrdtool 'update' 'myrrdfile.rrd' '--template' 'd2:d1' '1240729201:100:U'


cheers
tobi

-- 
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