Telegraf: input.snmp - octet counters with negative difference

Telegraf
1

Hi,

I was trying to implement an internet traffic monitoring via Telegraf.

I used input plugin [[inputs.snmp]]. Since monitored device reports just snmp1, I have to set
version = 1. This brings the limitation of use just 32-bit Octets counters (e.g. IF-MIB::ifInOctets.2 = Counter32)

Since these counters ‘flip-over’ to zero once the data type size limit is reached (maximum value for a 32 bit unsigned integer is 4,294,967,295), further use, monitoring and analysis of these data is very limited.
Subsequent data points with a negative difference of counters’ values (in the time when 32-bit limit of the counter is reached) make whole metric inapplicable.

It forced me to write down a separate script which gathers non-negative difference between octet counters and writes it into InfluxDb.

It would be nice to have such functionality implemented into Telegraf snmp input plugin.

2

You should be able to simply store the raw counter value in InfluxDB, and in your query use either non_negative_difference() or non_negative_derivative() depending on your exact need.