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From Nitin Borwankar <ni...@borwankar.com>
Subject Re: couchdb on 8 core redhat/fedora
Date Mon, 10 Aug 2009 02:13:27 GMT
I believe there are at least 4 spindles.  But I don't expect to be
continually writing or writing while generating indexes - this is meant to
be primarily a reference "datawarehouse" kind of read-only database - writes
will happen in batch mode once a day for a couple of hours during which time
no reads will be taking place.  All initial view generation will happen when
no writes are taking place.
Having views on separate disk from db is a good suggestion  I'll see about
the symlinks part as well.

Thanks much all for all the info - this has been extremely useful and
helpful

Nitin

37% of all statistics are made up on the spot
-------------------------------------------------------------------------------------
Nitin Borwankar
nborwankar@gmail.com


On Sun, Aug 9, 2009 at 2:42 PM, Chris Anderson <jchris@apache.org> wrote:

> On Sun, Aug 9, 2009 at 2:25 PM, Nitin Borwankar<nitin@borwankar.com>
> wrote:
> > On Sun, Aug 9, 2009 at 12:13 PM, Adam Kocoloski <kocolosk@apache.org>
> wrote:
> >
> >>
> >> Hi Nitin, Jan's right, if you're only building views from a single
> design
> >> doc you won't get much indexing speedup from multi-core at the moment.
>  We
> >> do spawn multiple couchjs processes (often one does the map and the
> other
> >> the reduce), but we don't map docs out to them simultaneously or
> anything.
> >>  Also, the Erlang process communicating with couchjs blocks and waits
> for
> >> the results when it sends data out.  Best,
> >>
> >> Adam
> >>
> >
> > Ok, so I could have multiple databases each with multiple design docs and
> > make a number of requests and have a number of couchjs processes spread
> out
> > across multiple cores right?
> >
> > I suppose what I am hearing is that views in a single design doc can
> become
> > a bottleneck but views in multiple design docs will get the benefit of
> > multiple couchjs processes.
> >
> > Since this part of my experiment is not couchapp based, I am completely
> fine
> > having a) multiple databases and b) multiple design docs per database.
> >
>
> Unless you have lots of disks, you won't gain performance from
> multiple dbs. However, you might do well you put views onto a
> different disk from the db file, if you'll be writing while generating
> indexes. or spread view files across disks with symlinks so disks
> don't have to seek as much to record view rows.
>
> > So this gives me the OS level scheduling of couchjs processes across
> cores,
> > I think.
> >
> > Nitin
> >
> >
> >
> > 37% of all statistics are made up on the spot
> >
> -------------------------------------------------------------------------------------
> > Nitin Borwankar
> > nborwankar@gmail.com
> >
>
>
>
> --
> Chris Anderson
> http://jchrisa.net
> http://couch.io
>

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