Counter difference graph

Question

Image that we have a time series with timestamps t_1, t_2 ... t_n. And a metric m with values m_1, m_2 ... m_n for the respective timestamps. Metric m is a counter so it will only increase. Then there is a second metric k that is calculated from two nearby measures of m:

k(n) = m(n) - m(n - 1)

Basically k indicates the difference between two m measurements. For example: n | 1 | 2 | 3 | 4 | m | 10 | 10 | 15 | 16 | k | 0 | 0 | 5 | 1 |

What would be the query to OpenTSDB or Bosun that will return k based on m.

So far, I've only found rate feature but it is limited in showing rate per minute and it doesn't show the actual difference.

Answer 1

You can try Axibase Time Series Database which is compatible with tcollector and scollector protocols and provides a rate transformation to calculate the deltas. The rate transformation returns the difference between consecutive values if the interval is set to 0. There is a boolean flag that controls how counter resets (negative deltas) are handled.

Here's a live example.

More details are available in this tutorial.