Modifying the Polling Rate

Add new RRA definitions

The first thing is to create new RRA definitions. The current defaults are in the toplevel “Defaults” file. I left those as is and created a new subtree /router-1min with the new RRA definitions in the /router-1min “Defaults” file. The definitions are completely dependent on what type of data you want to keep and how long you want to store it. See the RRDTool create function documentation for details.

# one point every minute for 2 days rra 1minAve AVERAGE:0.5:1:1880 # one point every 30 minutes for 1 week, both average and maximum rra 30minAves1 AVERAGE:0.5:30:336 rra 30minMaxs1 MAX:0.5:30:336 # one point every 2 hours for 50 days, both average and maximum rra 2hrAves1 AVERAGE:0.5:120:600 rra 2hrMaxs1 MAX:0.5:120:600 # one point every day for 600 days, both average and maximum rra 1dayAves1 AVERAGE:0.5:1440:600 rra 1dayMaxs1 MAX:0.5:1440:600

Add the new RRA definitions to the targetType Dictionary.

Add the new rra definitions to the targetType dictionary for the target you want to monitor.

Here is my definition from my /router-1min “Defaults” file. For this particular router interface I am interested only in “ifInOctets” and “ifOutOctets” at 1 minute intervals. The actual datasource definitions for “ifInOctets” and “ifOutOctets” are still in the rootlevel Defaults file.

targetType 1min-router-interface ds = "inInOctets, inOutOctets" view = "Octets: inInOctets ifOutOctets" rra = "1minAve, 30minAves1, 30minMaxs1, 2hrAves1, 2hrMaxs1, 1dayAves1, 1dayMaxs1"

Modify rrd-poll-interval in the target dictionary

This is from my /router-1min “Defaults” file.

Target --default-- inst = map(interface-name) snmp-community = secret snmp-host = %router% target-type = 1min-router-interface rrd-poll-interval = 60

Modify your crontab

Modify cron update times to run every minute of the hour.