Re: mod_proxy reverse proxy optimization/performance question

[Graham Leggett <mi...@sharp.fm>]

Roman Gavrilov wrote:

> I am using a reverse proxy to cache a remote site. The files are mostly 
> rpms, with varying sizes: 3-30M or more.
> Now if you have a number of requests for the same file which is not yet 
> cached locally, all of these requests will download the requested file 
> from the remote site.  It will slow down the speed of each download as 
> the throughput of the line will be split among all processes.
> So if there are lots of processes to download the same rpm from a remote 
> site, this can take lots of time to complete a request.
> This can bring apache to a state where it can not serve other requests, 
> as all available processes are already busy.

This is a mod_cache issue rather than a proxy issue, the best place to 
discuss something like this is dev@httpd.apache.org. (mod_cache was 
separated from mod_proxy in httpd v2.0, this fix never went into httpd 
v1.3 mod_proxy because it was a serious architecture change)

When mod_cache was separated from mod_proxy in httpd v2.0, one of the 
problems the new cache code was supposed to solve was this exact problem 
- whether this problem stayed solved in all the development to mod_cache 
that has been done in the last while is a good question.

Regards,
Graham
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