On Fri, May 29, 2009 at 2:51 AM, Ved <[email protected]> wrote:
>
> I have a webpage in which I read a text file for processing. My
> benchmark (ab) results show a much higher request / second than
> contents stored and accessed using memcached. And also the number of
> failed request is 0 when I am using disk IO where as when I am using
> memcached the number keeps going higher. What could be the possible
> reasons for memory IO being slower than disk IO, and the failed
> requests.

I think some of your assumptions may be incorrect. If you are using
the same file in every request your OS is probably using a cached copy
in memory. It won't hit the disk every time. While memcached does
store everything in memory which is fast, it transmits data over a
socket which is slow. You are really comparing using local memory vs.
using memory on a different machine.

I use memcached to reduce hits to my database which is much slower
than memcached. Sometimes I also use it to store objects that are
expensive to create. This is just a trade off between CPU and network
access.

-- 
David
blog: http://www.traceback.org
twitter: http://twitter.com/dstanek

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