Re: [issue] pmwebd graphite api performance issue

[Ken McDonell <kenj@xxxxxxxxxxxxxxxx>]

G'day Frank.

On 28/07/15 10:26, Frank Ch. Eigler wrote:
> ..
> That could work too, though doing it naively could involve O(#metrics**2)
> iteration, which could itself be heavy. ...
The old computational complexity meets reality trap ... not all 
operations have the same cost.
I'll wager that for any von Neumann machine with real values of #metrics 
(and #instances), an O(#metrics**2) times for loop with simple test 
(p->indom == indom_of_interest && p->done == 0) will beat the pants off 
any O(#metrics) times loop with pmGetInDomArchive() + free()
> ... Doing it the cache way in pmwebd
> turned out to be easy:
OK, sounds good.

Cheers, Ken.