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From Harsh J <qwertyman...@gmail.com>
Subject Re: Streaming reporter counter update
Date Wed, 02 Feb 2011 03:58:40 GMT
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 <kwiley@keithwiley.com> 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               kwiley@keithwiley.com               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

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