Two important configuration parameters of HDR (High Dynamic Range)
histogram are 1) integer value range and 2) the value precision.
For example, let's assume that the range is 0 - 3,600,000,000 and the
value precision = 3 ( (means that the accuracy of any value within the
range will be better than 1/1000 of the value)
Under these settings HDR histogram can track and analyze the counts of
observed response times ranging between 1 microsecond and 1 hour in
magnitude with the following resolutions :
1 microsecond resolution up to 1 millisecond,
1 millisecond (or better) resolution up to one second
1 second (or better) resolution up to 1,000 seconds.
3.6 seconds (or better) resolution up to 1 hour
The memory footprint HDR depends on the dynamic range and precision chosen
(As Isuru already pointed for a given dynamic range and precision the
memory foot print is fixed). There is a way to compute the memory foot
print using these values .
On Fri, Oct 14, 2016 at 9:33 AM, Isuru Perera <isu...@wso2.com> wrote:
> In Carbon Metrics , the TImers and Histograms use the default reservoir
> provided by the Dropwizard Metrics  library.
> Currently there is no support to change this reservoir implementation in
> Carbon Metrics. Therefore we are working on supporting a set of reservoirs
> in Carbon Metrics.
> The HdrHistogram  is a popular histogram implementation and it has lot
> of useful features for us. For more info, see . One major advantage for
> us is that HDR Histogram maintains a fixed cost in both space and time.
> When using HdrHistogram as reservoir, we can also a solve a problem with
> the default Exponentially Decaying Reservoir when publishing metrics events
> to WSO2 Data Analytics Server. The problem is explained in . With HDR
> Histogram, we can reset the snapshot when reporting to WSO2 DAS.
> We are going to integrate HDR Histogram into the next Carbon Metrics
> release, which is based on Carbon 5.x
> We don't have plans to do any release of Carbon Metrics based on Carbon
> 4.x. If anyone needs the HDR Histogram as a reservoir, we'll be able to do
> changes in 1.x.x  branch and do a release.
> Best Regards,
>  https://github.com/wso2/carbon-metrics
>  http://metrics.dropwizard.io
>  https://github.com/HdrHistogram/HdrHistogram
>  http://hdrhistogram.github.io/HdrHistogram/
>  http://taint.org/2014/01/16/145944a.html
>  https://github.com/wso2/carbon-metrics/branches
> Isuru Perera
> Associate Technical Lead | WSO2, Inc. | http://wso2.com/
> Lean . Enterprise . Middleware
> Contact: +IsuruPereraWSO2 <https://www.google.com/+IsuruPereraWSO2/about>
WSO2, Inc. (http://wso2.com)
Email : mali...@wso2.com
Mobile : 0770704040
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