[Zope-dev] RFC: ETag support for zope.browserresource

[Christian Theune]

On 08/10/2010 12:37 AM, Sidnei da Silva wrote:
> On Mon, Aug 9, 2010 at 3:25 PM, Marius Gedminas<marius at gedmin.as>  wrote:
>> I've added ETag support for zope.browserresource in a branch:
>> http://zope3.pov.lt/trac/changeset/115596
>>
>> Does anybody have any comments/objections?  If not, I'd like to merge
>> this to trunk and release zope.browserresource 3.11.0.
>
> +1 as long as there's a way to disable or configure how it's computed.
> There's some information about issues with ETags here:
>
>    http://developer.yahoo.com/performance/rules.html#etags
>
> I see that your implementation uses last-modified + size, which should
> generally be fine. However if you're load-balancing across two
> different servers and the timestamps don't match then the ETag is
> useless.
>
> On a completely different note, I see that the File object reads the
> whole file into memory. Hum. Maybe RAM is cheaper than Disk these days
> and it doesn't matter, but reading whole files into memory generally
> raises a red flag for me.

IOPS aren't cheap nowadays. The IOPS/MB have had the issue that the MB 
kept increasing a lot in disks but the IOPS didn't catch up that much, 
so it may not even be a RAM issue but throughput/caching/IOPS.

-- 
Christian Theune · ct at gocept.com
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