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From André Warnier>
Subject Re: [users@httpd] Request concurrency issue
Date Sun, 22 Nov 2009 00:23:09 GMT
Toomas Aas wrote:
> Hello!
> I run Apache 2.2.11 with prefork MPM on FreeBSD 6.4. This is a pretty standard 
> installation done from FreeBSD ports. It has a behaviour that makes me 
> curious.
> Say, I open a browser and enter request for 
> The file begins to load in the browser window.
> While the file is loading, I open another browser tab and enter the same 
> request there.
> The file in second tab doesn't begin to load until it has completed loading in 
> the first tab.
> So - if the same client requests the same resource from the server multiple 
> times, the requests are not handled in parallel, but sequentially.
> If the same client requests different resources, the requests are handled in 
> parallel, i.e. I can load LargeTextFile.txt and LargeTextFile2.txt 
> simultaneously.
> There is no problem with available child processes, if I look the output of 
> server-status I see multiple idle child processes waiting for requests.
> The reason why I'm investigating this is that we have a web app written in 
> JavaScript/PHP which sends multiple concurrent requests from browser to 
> server, and developers are worried that this kind of behaviour slows down the 
> application. I've been told that this kind of behaviour isn't observed on 
> other servers but only on this particular server set up by me. The only other 
> web server I currently have access to is Apache 2.2.13 running on FreeBSD 7.2 
> (also set up by me) and it seems to behave the same. So maybe the problem is 
> me ;)
> In addition to simply loading .txt files I've also tried with .php scripts, 
> and the results are identical. So I guess the problem is not specific to a 
> handler but is more generic.
> What do I have to do to achieve the wanted behaviour (concurrent handling of 
> identical requests from the same client)?
Are you absolutely sure that it is not just a behaviour from the browser ?
For example, if you open two separate command windows, and start in each 
a "wget" for the same file (or curl, or lwp-request), do you observe the 
same behaviour ?

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