[Zope-dev] Serving big files thru zope?

Paul Winkler pw_lists at slinkp.com
Tue Mar 2 16:56:28 EST 2004


On Tue, Mar 02, 2004 at 07:06:31PM +0100, Dieter Maurer wrote:
(snip)
> I interpreted these observations in the following way:
> 
>   *  time is dominated by the disc access
> 
>   *  time is largely independent of the object size (if
>      the object is in the OS disc cache)
> 
>   *  ZEO overhead is about 1 to 3 ms per object.

Hmm. I wondered if ZEO overhead per-object was significant,
but this seems not too bad.

If I read OFS/Image.py correctly, the pdata chunks are
65536 bytes.  So a 40 MB file would split up into
about 640 chunks, so ZEO overhead by your calculations
should be roughly 1-2 seconds.
This does not account for the order of magnitude difference
I am seeing (initial load from filestorage: 0:03.87,
initial load from zeo: 0:33.54).

-- 

Paul Winkler
http://www.slinkp.com
Look! Up in the sky! It's PROTO FLASH TROMBONIST!
(random hero from isometric.spaceninja.com)



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