I have collectd sending time series data to influxdb, more specifically the disk plugin.
When I get data for a given time frame I can see that the values are incremental:
SELECT * FROM "disk_write" WHERE time > now() - 5m and type='disk_ops' and instance='sdb3';
So to get the actual value that will be used to draw a point in the final graph I would need to substract the previous value from the last value.
2019-02-28T14:42:08.139895389Z,sdb3,disk_ops,144771581 2019-02-28T14:42:18.139785832Z,sdb3,disk_ops,144771811 144771811 - 144771581 = 230
And I would need to do this for each interval in the given time frame.
Is there some special crafted query I can use so influxdb calculates and sends me automatically the substracted value from NEXT - PREVIOUS intervals?
I hope it makes sense.
Please help. THanks in advance