Increasing quality graph resolution

madengineer

I've been making extensive use of the connection quality monitoring graph (delay and packet loss vs. time) to keep track of persistent issues my ISP has been having. Although it's a very useful tool, I was having trouble finding a way to increase its resolution for historical data.

After a bit of digging, it looks like the timesteps used are in /var/db/rrd/updaterrd.sh, which in turn is generated from a hardcoded template in /etc/inc/rrd.inc. I then came up with this to increase log resolution (using find for the loop so it works in both Bourne and C derivative shells):

find /var/db/rrd -name \*.rrd -exec rrdtool tune '{}' RRA#0:=120000 RRA#1:=72000 RRA#2:=18600 RRA#3:=22840 ';'

This, of course, increases database size substantially (18.6x standard).

To make this higher-resolution data viewable, I then edited /usr/local/www/status_monitoring.php, removing the disabled attribute from lines in the switch starting on line 828, and changing default resolution (selected) according to my preferences: status_monitoring.zip

Does anyone foresee issues with this, beyond the increased system resources required?

Derelict

RRD intentionally aggregates data into larger intervals as the data gets older.

The monitoring graphs are intended to provide troubleshooting information, not be a high-resolution, historical archive. For that you can query the device using something like cacti or zabbix or a plethora of others.

Setting 8 hours x 1 minute resolution is pretty comprehensive. Anything longer than 8 hours and the resolution will be reduced.