Group is more of a meta-data thing. For instance, one may want all FileSystem related counters under a single namespace (which would be a Group, here).
On Wed, Feb 2, 2011 at 2:17 AM, Keith Wiley <[email protected]> wrote: > Ah, so count doesn't "set" the count, it increments it, meaning I shouldn't > increment it each time. That would result in some sort of strange > exponential counter. I should just pass 1 every time. I get it. > > I'm still unclear on the distinction between the group and the individual > counter, but I'll read up on that on my own. > > Thanks. > > On Feb 1, 2011, at 12:31 , Harsh J wrote: > >> A 'group' is a set of counters (like 'Map-Reduce Framework' in default >> counters -> That's a group name). A 'counter' needs a name to signify >> what it is about. >> >> The increment is what the 'amount' signifies. Generally 1, but can be >> any amount you need to increment the current count by. All counters >> are of Long type. Floats are not acceptable AFAIK. >> >> Example: >> reporter:counter:Aliens,Mars,1 would +1 the global counter >> [Aliens].Mars and reporter:counter:Aliens,Unknown,10 would +10 the >> global counter [Aliens].Unknown. >> >> Counters are aggregated together across all launched tasks, so you >> don't need to worry about aggregating them yourselves. Each Map/Reduce >> task needs only to count its own needed counters up from 0. > > > ________________________________________________________________________________ > Keith Wiley [email protected] > www.keithwiley.com > > "I used to be with it, but then they changed what it was. Now, what I'm with > isn't it, and what's it seems weird and scary to me." > -- Abe (Grandpa) Simpson > ________________________________________________________________________________ > > > > -- Harsh J www.harshj.com
