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From Niklas Edmundsson <ni...@acc.umu.se>
Subject Re: svn commit: r468373 - in /httpd/httpd/trunk: CHANGES modules/cache/mod_cache.c modules/cache/mod_cache.h modules/cache/mod_disk_cache.c modules/cache/mod_disk_cache.h modules/cache/mod_mem_cache.c
Date Fri, 27 Oct 2006 16:37:25 GMT
On Fri, 27 Oct 2006, Graham Leggett wrote:

>>> Err. We had the data in memory, we are going to read it back from disk
>>> again just in order to not block ? That's nonsense.
>>
>> Agreed.
>
> Please explain.
>
> This is a disk cache. Why would you write expensive bucket data to cache,
> and then expensive bucket data to the network?
>
> That's plain stupid.

And when you have a file backend, you want to hit your disk cache and 
not the backend when delivering data to a client. People might think 
that this doesn't matter, but for large files, especially larger than 
RAM in your machine, you usually go disk-bound without much help from 
the OS disk cache.

Also, httpd seems to be faster delivering data by sendfile than 
delivering data from memory buckets. That's more of a performance bug 
in httpd though.

/Nikke
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