Histograms need to be clear after x seconds

[laullon]

Describe the bug On histograms metrics we are sending the values (mean, max, min, etc...) calculated over the life time of the adapter, and that it's causing for example to show an average request duration when really there is no requests and it should be 0 or no data.

Expected behavior Send the histogram calculated values for the last X seconds, in other words, clear the histogram data every X seconds. I think it should be between 30 or 60 seconds by default, but could be also useful to give user the posibilito to change it.

[venilnoronha]

This seems to be an implementation issue as mentioned in rcrowley/go-metrics#150.

[laullon]

No, is not.

[laullon]

Please take a look of thees two links:

• https://blog.filippo.io/understanding-metrics/
• http://taint.org/2014/01/16/145944a.html

They describe the problem, and the solution.

(cc: @vikramraman)