Re: [Ganglia-developers] Overlay timeshifted data

[Vladimir V. <vl...@ve...>]

Obviously this is a first pass at this feature. I have thought about 
comparing arbitrary time periods but I thought a generic UI for that may 
be tricky to implement. Also currently this allows overlaying only a 
single metric. It is possible to do overlaying on aggregate graphs or 
reports but then it may get messy since you double the number of lines.

We'll see.

Vladimir

On Wed, 16 May 2012, Aaron Nichols wrote:

> On Wed, May 16, 2012 at 5:54 PM, Vladimir Vuksan <vl...@ve...> wrote:
>       There is a blog post about a new feature in Ganglia Web called overlay
>       timeshifted data
>
>       http://ganglia.info/?p=543
> 
> 
> This is awesome. We've been working on a similar ability just using php based reports. Two things additional we
> wanted to be able to do besides just comparing one time period to the previous:
> 
> a) Compare two arbitrary time periods. In our case we run performance / load tests & want to be able to compare a
> loadtest run X minutes ago with one run Y minutes ago. The delta between X & Y is the timeshift. We can do this for
> any given interval (1h, 2h, 1d, 1w, etc)
> 
> b) Rather than just show the two metrics overlayed, we wanted to calculate the % difference between two periods. This
> becomes more useful in production where we want to know if a particular trend has changes more than N% over some
> period of time (say post-deployment). 
> 
> Down the road we also want to try to normalize the "previous period" by averaging multiple previous periods. For
> example, compare Monday this week w/ the average of the last 3 Monday's. 
> 
> I can pass along a blog post here with more details when I get it written up - but being able to do those two things
> was pretty crucial to us & may be useful to others. 
> 
> Thanks for the continued work on this - awesome progress. 
> 
> Aaron
> 
>