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From Cemal Dalar <cemal.da...@gmail.com>
Subject Re: Read Performance
Date Thu, 01 Apr 2010 07:06:48 GMT
Hi James,

I don't know how to get the below statistics data and calculate the access
times (read/write in ms) in your previous mails. Can you explain a little?
Iike to work on it also.

CD

On Thu, Apr 1, 2010 at 4:15 AM, Jonathan Ellis <jbellis@gmail.com> wrote:

> On Wed, Mar 31, 2010 at 6:21 PM, James Golick <jamesgolick@gmail.com>
> wrote:
> > Keyspace: ActivityFeed
> >         Read Count: 699443
> >         Read Latency: 16.11017477192566 ms.
>
> >                 Column Family: Events
> >                 Read Count: 232378
> >                 Read Latency: 0.396 ms.
> >                 Row cache capacity: 500000
> >                 Row cache size: 62768
> >                 Row cache hit rate: 0.007716049382716049
>
> This says that
>
>  - recent queries to Events are much faster than the lifetime average
> for your Keyspace
>  - even though you have almost no row cache hits (~1700 out of 232000
> reads)
>
> Not sure what to make of that, tbh.  If it were me I would try to
> reproduce on a test machine w/o all that pesky live traffic confusing
> things.
>
> -Jonathan
>

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