<div dir="ltr"><div>I was hoping someone could help me understand how values are computed in RRD.</div><div>I got a temp database (create below). I got a loop that adds an update ever ~2 minutes.</div><div><br></div><div>rrdtool info says the DS got known values for the last two columns (ext_temperature, ext_humidity). </div><div>Yet when I do a graph/fetch, I'm getting NaNs for the last two columns.<br></div><div><br></div><div>Thanks,</div><div>===============</div><div><br></div><div>Create:</div><div>rrdtool create $HOME/.xdg/data/nest_thermostat.rrd \</div><div>--step '200' \</div><div>'DS:temperature:GAUGE:600:0:100' \</div><div>'DS:humidity:GAUGE:600:0:100' \</div><div>'DS:target:GAUGE:600:0:100' \</div><div>'DS:mode:GAUGE:600:0:10' \</div><div>'DS:state:GAUGE:600:0:10' \</div><div>'DS:fan:GAUGE:600:0:1' \</div><div>\</div><div>'DS:ext_temperature:GAUGE:1500:0:100' \</div><div>'DS:ext_humidity:GAUGE:1500:0:100' \</div><div>\</div><div>'RRA:AVERAGE:0.5:1:2016' \</div><div>'RRA:AVERAGE:0.5:1:4032' \</div><div>'RRA:AVERAGE:0.5:6:1440' \</div><div>'RRA:AVERAGE:0.5:6:4416' \</div><div>'RRA:AVERAGE:0.5:12:4392' \</div><div>'RRA:AVERAGE:0.5:24:4380' \</div><div>'RRA:AVERAGE:0.5:48:4380'</div><div><br></div><div>Update logs:</div><div><div>2018-01-22 16:54:40.787444: Updating RRD with N:67:50:65:2:0:0:U:U</div><div>2018-01-22 16:54:40.788156: Updating RRD with N:U:U:U:U:U:U:56.5:65</div><div>2018-01-22 16:56:11.899996: Updating RRD with N:67:50:65:2:0:0:U:U</div><div>2018-01-22 16:56:11.900661: Updating RRD with N:U:U:U:U:U:U:56.5:65</div></div><div><br></div><div>rrdtool info:</div><div><div>$  rrdtool info nest_thermostat.rrd  | grep ext</div><div>ds[ext_temperature].index = 6</div><div>ds[ext_temperature].type = "GAUGE"</div><div>ds[ext_temperature].minimal_heartbeat = 1500</div><div>ds[ext_temperature].min = 0.0000000000e+00</div><div>ds[ext_temperature].max = 1.0000000000e+02</div><div>ds[ext_temperature].last_ds = "56.5"</div><div>ds[ext_temperature].value = 3.6216500000e-02</div><div>ds[ext_temperature].unknown_sec = 62</div><div>ds[ext_humidity].index = 7</div><div>ds[ext_humidity].type = "GAUGE"</div><div>ds[ext_humidity].minimal_heartbeat = 1500</div><div>ds[ext_humidity].min = 0.0000000000e+00</div><div>ds[ext_humidity].max = 1.0000000000e+02</div><div>ds[ext_humidity].last_ds = "65"</div><div>ds[ext_humidity].value = 4.1665000000e-02</div><div>ds[ext_humidity].unknown_sec = 62</div></div><div><br></div><div>Fetch:</div><div><div>$  rrdtool fetch nest_thermostat.rrd AVERAGE | tail -n5</div><div>1516668600: 6.6830290005e+01 4.9873350750e+01 6.4835355975e+01 1.9949340300e+00 0.0000000000e+00 0.0000000000e+00 -nan -nan</div><div>1516668800: 6.6834396100e+01 4.9876415000e+01 6.4839339500e+01 1.9950566000e+00 0.0000000000e+00 0.0000000000e+00 -nan -nan</div><div>1516669000: 6.6999548755e+01 4.9999663250e+01 6.4999562225e+01 1.9999865300e+00 0.0000000000e+00 0.0000000000e+00 -nan -nan</div><div>1516669200: 6.6910302075e+01 4.9933061250e+01 6.4912979625e+01 1.9973224500e+00 0.0000000000e+00 0.0000000000e+00 -nan -nan</div><div>1516669400: -nan -nan -nan -nan -nan -nan -nan -nan</div></div></div>