[Zope] large images to a database via zope.

marc lindahl marc@bowery.com
Thu, 19 Apr 2001 02:58:40 -0400


Since you're collecting evidence, can you please try the exact same
experiment, except serving up your big file via ExtImage and/or localFS?
Thanks,
Marc

> From: ethan mindlace fremen <mindlace@digicool.com>
> Date: Tue, 17 Apr 2001 17:58:41 -0400
> To: zope@zope.org
> Subject: Re: [Zope] large images to a database via zope.
> 
> --On Tuesday, April 17, 2001 11:51:11 +0100 Toby Dickenson
> <tdickenson@devmail.geminidataloggers.co.uk> wrote:
>> On Tue, 17 Apr 2001 05:00:35 -0400, ethan mindlace fremen
>> <mindlace@digicool.com> wrote:
>>> Well, a thread is locked for the entire time it is writing out to the
>>> end  user. So get 4 simultaneous requests for a large file, and your
>>> site is now  unresponsive (in a stock install.)
>> 
>> Im sure thats not true.
> 
> Here is my evidence:
> 
> Take zope (the .tgz) and stick it in your zope.
> 
> Get NetAnts (a windows program) and tell it you want to make >4
> simultaneous "offset" requests for the same file, then download zope.tgz.
> 
> Try to get any other file from that zope with a regular browser, or run a
> light "ab" against it.
> 
> During the time that you are serving those offsets (which actually
> translates into serving the entire file), if # of requests > number of
> threads, your server will not answer to you.
> 
> Annoyingly, mod_proxy's cache mechanism decides that *it* can't handle
> offset requests, so it doesn't help any to cache.
> 
> This is actually a general problem for any non-filesystem image serving:
> Can you ask for BLOBS by offset?