[rrd-users] RRD Graphs with bad averaging of missing data?

[Matt Elias]

I no longer have the rrd for the original sample graph I posted but here 
is a short exert from another anomaly.
<!-- 2014-04-10 09:42:48 CDT / 1397140968 --> 
<row><v>2.1800000000e+02</v></row>
<!-- 2014-04-10 09:43:00 CDT / 1397140980 --> 
<row><v>2.1800000000e+02</v></row>
<!-- 2014-04-10 09:43:12 CDT / 1397140992 --> 
<row><v>2.1800000000e+02</v></row>
<!-- 2014-04-10 09:43:24 CDT / 1397141004 --> <row><v>NaN</v></row>
<!-- 2014-04-10 09:43:36 CDT / 1397141016 --> <row><v>NaN</v></row>
<!-- 2014-04-10 09:43:48 CDT / 1397141028 --> <row><v>NaN</v></row>
<!-- 2014-04-10 09:44:00 CDT / 1397141040 --> <row><v>NaN</v></row>
<!-- 2014-04-10 09:44:12 CDT / 1397141052 --> <row><v>NaN</v></row>
<!-- 2014-04-10 09:44:24 CDT / 1397141064 --> <row><v>NaN</v></row>
<!-- 2014-04-10 09:44:36 CDT / 1397141076 --> 
<row><v>2.1449311575e+02</v></row>
<!-- 2014-04-10 09:44:48 CDT / 1397141088 --> 
<row><v>2.1800000000e+02</v></row>
<!-- 2014-04-10 09:45:00 CDT / 1397141100 --> 
<row><v>2.1800000000e+02</v></row>
As I have suspected, it is an issue of averaging. I don't know how to 
setup my RRDs properly. These are not rates, they are temperatures.

So what I am aiming for is the following graph time periods at about 780 
pixels wide (maybe up to 900), 1 hr, 2 hr, 6 hr, 12 hr, 24 hr, 3 day, 7 
day, 14 day, 1 month, 4 month, 1 year, 2 year & 10 year. I figure 780 * 
5s = 65mins. I'd like no NaNs used in any averaging and I'd prefer 
blanks in the graph for missing updates. How should I setup my RRDs? The 
following is how I understand I should do it using the 1s step (still 
unsure about heartbeat though).

RRDs::create("$rrd/bin$t-$n.temps.rrd",
"-s", "1",
"DS:Temp:GAUGE:5:U:U",
"RRA:AVERAGE:0:1:900",  # track 900 1sec samples for 15min graph
"RRA:AVERAGE:0:5:900",  # 4500 1sec samples, 1hr graph
"RRA:AVERAGE:0:10:900", # 9000 1sec samples, 2hr graph
"RRA:AVERAGE:0:30:900", # 27000 1sec samples, 6hr graph
"RRA:AVERAGE:0:60:900", # 54000 1sec samples, 12hr graph
"RRA:AVERAGE:0:120:900",# 108000 1sec samples, 24hr graph
"RRA:AVERAGE:0:360:900",   # 3day graph
"RRA:AVERAGE:0:840:900",   # 1 week graph
"RRA:AVERAGE:0:1680:900",  # 2 week graph
"RRA:AVERAGE:0:3600:900",  # 1month graph
"RRA:AVERAGE:0:43800:900", # 1yr graph
"RRA:AVERAGE:0:87600:900", # 2yr graph
"RRA:AVERAGE:0:438000:900");  # 10yr graph

Matt