Port traffic slope graph / alert rule

Hi guys …
I would like to discuss about traffic behaviour analisis.
8 years ago , I was using cacti , and founded very usefull to use rrd databases to create traffic rate slope to detect traffic events (up and down).
Im trying to achieve same with data available on mysql database but there is a missing value.
I have:

It would be possible to create slope trigger alert rule if you can keep the
ifInOctets_rate_prev value …

Other alternative , would be to tweak the rdd database to create a slope function and create the traffic slope.
So , for future versions:
Can you keep the ifInOctets_rate_prev and ifOutOctets_rate_prev values on the database for slope calculation and alert rule usage?
.For Current or future versions:
Is it possible to tweak the rrd parameter to generate port traffic slope ?
if not …
Is it possible te see cacti generated rrd graph on lnms
Hope we can work on this.