使用rrdtool監控人民幣匯率

1. 使用rrdtool建立rrd文件，對人民幣對美元匯率做5分鐘統計，建立AVERAGE和MAX兩種類型的RRA歸檔

rrdtool create rmbrate.rrd \
-s 300 \
-b `date +%s` \
DS:rmbrate:GAUGE:600:U:U \
RRA:AVERAGE:0.5:1:603 \
RRA:AVERAGE:0.5:6:603 \
RRA:AVERAGE:0.5:24:603 \
RRA:AVERAGE:0.5:228:800 \
RRA:MAX:0.5:1:603 \
RRA:MAX:0.5:6:603 \
RRA:MAX:0.5:24:603 \
RRA:MAX:0.5:288:603

2. 通過Yahoo提供的匯率查詢解決取得當前匯率，並存入rrd文件。

#!/bin/bash
PATH='/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin'
timestamp=`date +%s`
rrdfile='/home/sandbox/rmb/rmbrate.rrd'
rmbrate=`curl 'http://download.finance.yahoo.com/d/quotes.csv?s=USDCNY=X&f=sl1d1t1&e=.csv' 2>/dev/null | awk -F, '{print $2}'`
rrdtool update $rrdfile ${timestamp}:${rmbrate}

3. 加一個crond對匯率做5分鐘記錄。

*/5 * * * * /home/sandbox/rmb/rmb.sh &>/dev/null

4. 使用php腳本展示人民幣匯率rrd圖。

<?php
header("Content-type:image/png");
$cmd='
/usr/bin/rrdtool graph - \
-h 120 -w 500 \
--start now-1d \
-v "RMB/USD" --title "RMB-USD Rate" \
DEF:rmbrate=/home/sandbox/rmb/rmbrate.rrd:rmbrate:MAX AREA:rmbrate#00CF00FF:"RMB Rate" \
GPRINT:rmbrate:LAST:"Current\:%lf %s" \
GPRINT:rmbrate:AVERAGE:"Average\:%lf %s" \
GPRINT:rmbrate:MAX:"Max\:%lf %s" \
COMMENT:"\n"
';
passthru($cmd);
?>

最後展示的效果