[Zope] large images to a database via zope.

[ethan mindlace fremen]

--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?

~ethan
--
-mindlace-