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From: Paul Davis <paul.joseph.davis@gmail.com>
Date: Wed, 10 Nov 2010 12:15:01 -0500
Message-ID: <AANLkTinUO=AJe8=Sxztvt5U202W=X38pS=bH1ygROPb6@mail.gmail.com>
Subject: Re: Understanding _stats (again)
To: user@couchdb.apache.org
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On Wed, Nov 10, 2010 at 10:17 AM, Sebastian Cohnen
<sebastiancohnen@googlemail.com> wrote:
> Hey list,
>
> since the writing of http://wiki.apache.org/couchdb/Runtime_Statistics it looks like the output of _stats has changed once more. e.g. "count" is no longer available for each stat, "current" is.
>
> * Is "sum" (which looks new) the new "count"?

Sum is a running sum of values aggregated from the collector.
Generally, its only intended for things like time per request.

> * What range do I get, when calling /_stats without a range? What does mean/min/max etc mean in this case?

You get a special range that is "since the server started".

> I'm a bit confused and others are too (at least I think so). When a dev willing to be interviewed, I'd love to create a writeup, update the wiki or whatever :)


Feel free to find me on IRC in about an hour to ask any questions you
have. Or feel free to just keep asking questions here.

>
> Best
>
> Sebastian
>
>

I know some people don't like the Erlang too much, but the amount of
code is fairly small. You can check the handle_call, new_value,
add_value, and rem_value functions in the aggregator [1] to get a
pretty good idea on how it all works.


HTH,
Paul Davis

[1] https://github.com/apache/couchdb/blob/trunk/src/couchdb/couch_stats_aggregator.erl