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rrdtool使用案例
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1.创建一个rrd文件
[root@OCM home]# rrdtool create test.rrd --step 5 DS:testds:GAUGE:8:0:U RRA:AVERAGE:0.5:1:17280 RRA:AVERAGE:0.5:10:3456 RRA:AVERAGE:0.5:100:1210

创建一个rrd文件,每5秒钟产生一个数据,心跳8秒,最小值0,最大值unkown
第一个RRA
  0.5 超过一半unkown,平均值为unkown
  1 :取一个作聚合
  17280 :保留1天   86400s/5s
2.查看产生rrd的内容
[root@OCM home]# rrdtool info test.rrd 
filename = "test.rrd"
rrd_version = "0003"
step = 5
last_update = 1445267583
header_size = 928
ds[testds].index = 0
ds[testds].type = "GAUGE"
ds[testds].minimal_heartbeat = 8
ds[testds].min = 0.0000000000e+00
ds[testds].max = NaN
ds[testds].last_ds = "U"
ds[testds].value = 0.0000000000e+00
ds[testds].unknown_sec = 3
rra[0].cf = "AVERAGE"
rra[0].rows = 17280
rra[0].cur_row = 4421
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[1].cf = "AVERAGE"
rra[1].rows = 3456
rra[1].cur_row = 3253
rra[1].pdp_per_row = 10
rra[1].xff = 5.0000000000e-01
rra[1].cdp_prep[0].value = NaN
rra[1].cdp_prep[0].unknown_datapoints = 6
rra[2].cf = "AVERAGE"
rra[2].rows = 1210
rra[2].cur_row = 386
rra[2].pdp_per_row = 100
rra[2].xff = 5.0000000000e-01
rra[2].cdp_prep[0].value = NaN
rra[2].cdp_prep[0].unknown_datapoints = 16
3.给rrd提供数据
[root@OCM home]# rrdtool update test.rrd N:$RANDOM

[root@OCM home]# cat genval.sh 
#!/bin/bash
while true; do
 rrdtool update test.rrd N:$RANDOM
 sleep 5
done
[root@OCM home]# bash -n genval.sh 
[root@OCM home]# bash -x genval.sh 
4.画图
[root@OCM home]# rrdtool graph a.png --step 5 -s  1445268510 -t Test -v vtest DEF:vtest=test.rrd:testds:AVERAGE LINE1:vtest#ff0000:testline