[rrd-users] Separating data by time of day

[Matthew Booth]

I collect in and out volume data from my router continuously at 15
minute intervals. I use this to graph when I use bandwidth, and how
much. I currently graph daily, weekly and monthly totals, as well as
rate graphs.

My ISP has the concept of a 'peak' period between 8am and 6pm. I would
like to separate my daily, weekly and monthly totals into bandwidth used
in the peak period, and bandwidth used outside that time. The following
RPN zeroes all data points outside of that time period:

LTIME,86400,%,DUP,28800,GT,EXC,64800,LE,+,2,EQ,in,0,IF

My problem is that I can't find a way to use this to create totals over
a wider period than a single step. If I want to create a daily total,
then I can't just use a step size of 1 day and multiply by 86400,
because the time of that coalesced data point will be midnight, and I'll
get a zero for the whole day. If I use a smaller step size, I can't find
a way to aggregate multiple CDEF data points to create a daily total.
Although I haven't tried it yet, the documentation tells me that COMPUTE
won't work either, because you can't use TIME/LTIME.

Is there anything I missed?

Thanks,

Matt