Hi all,

I would like to get feedback on $subject and see if I'm missing something. The impact of this is simply less resource consumption and by that we can support even greater number of hosts [1] and vms in the system.

If you think more relaxed statistics collection will affect a core flow let me know - as far as I see I didn't spot anything critical.

The overhead of a cycle per host something like that: 2 roundtrips per host in a cycle, (vm + host stats) and tons of memory allocation for char[] -> json-> maps of maps -> VM/Vds statistics -> Maps -> serialiazing to DB. 

To minimize the effect of this change we can leave a call to 'list' verb to at least detect vms existence in the same rate as today.

Pros
- Engine has rore resources to support more hosts/vms/other activities of the engine
- Vdsm will have more resources as well (need to tweak vdsm to collect in the same
frequency)
- less DB writes and reads, approx half of what the system will do in the in its lifefpan (cause this is what is mainly does all the time)

Cons
- DWH/Dashboard will have less entries, I'm not sure what is graphical affect given our hourly resolution (cmiiw here)


[1] https://bugzilla.redhat.com/show_bug.cgi?id=1430876