Hi all, Short version: Why is AVERAGE producing difference values to MAX from the same RRA, when I am keeping 2 years worth of data and query for data gathered only a month or two ago?
Full version: I have some RRDs that keep 5 minutes samples for 2 years, for tracking router/switch/firewall/server interfaces speeds; They look like this; me@server:~$ rrdtool info /var/lib/cacti/rra/router1_traffic_in_11666.rrd filename = "/var/lib/cacti/rra/router1_traffic_in_11666.rrd" rrd_version = "0003" step = 300 last_update = 1386606906 ds[traffic_in].type = "COUNTER" ds[traffic_in].minimal_heartbeat = 600 ds[traffic_in].min = 0.0000000000e+00 ds[traffic_in].max = 1.0000000000e+09 ds[traffic_in].last_ds = "1601976753" ds[traffic_in].value = 1.6551294400e+06 ds[traffic_in].unknown_sec = 0 ds[traffic_out].type = "COUNTER" ds[traffic_out].minimal_heartbeat = 600 ds[traffic_out].min = 0.0000000000e+00 ds[traffic_out].max = 1.0000000000e+08 ds[traffic_out].last_ds = "72738702" ds[traffic_out].value = 1.5563000000e+04 ds[traffic_out].unknown_sec = 0 rra[0].cf = "AVERAGE" rra[0].rows = 230400 rra[0].pdp_per_row = 1 rra[0].xff = 5.0000000000e-01 rra[0].cdp_prep[0].value = NaN rra[0].cdp_prep[0].unknown_datapoints = 0 rra[0].cdp_prep[1].value = NaN rra[0].cdp_prep[1].unknown_datapoints = 0 rra[1].cf = "MAX" rra[1].rows = 230400 rra[1].pdp_per_row = 1 rra[1].xff = 5.0000000000e-01 rra[1].cdp_prep[0].value = NaN rra[1].cdp_prep[0].unknown_datapoints = 0 rra[1].cdp_prep[1].value = NaN rra[1].cdp_prep[1].unknown_datapoints = 0 As you can see, 230400 rows in each rra, recording data in 5 minute steps; (230400*5)=1152000 minutes, 1152000/60/24/365 = 2.19 years I want full accuracy of data for 2 years. I have a problem though when I generate graphs from this RRD file. I am using Cacti to gather data from devices using SNMP, I have modified Cacti to create these two year RRDs for me. Cacti generates a graph like this; http://i.imgur.com/UZR4QYU.png When generate a graph by hand on the CLI I get this; http://i.imgur.com/jcXHYu5.png The difference is that I use "DEF:in="my.rrd":traffic_in:MAX" where as Cacti uses "AVERAGE". If I change my data source to be AVERAGE I get the same graph Cacti produces. Simple enough. So why is AVERAGE producing a different value to MAX here, when I am keeping 2 years worth of data and query for data gathered only a month or two ago? Many thanks all, James, _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
