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From Bryan McQuade <bmcqu...@google.com>
Subject Re: Fast by default
Date Wed, 02 Jun 2010 00:16:55 GMT
On Tue, Jun 1, 2010 at 6:17 PM,  <tokiley@aol.com> wrote:
>> There is zero reason for us to avoid putting deflate into the default
>> configuration.
>
> Sorry. There ARE (good) reasons to avoid doing so.
>
> I'm the one who wrote the FIRST mod_gzip module for Apache 1.x series
> so you would think I'd be a strong advocate of 'auto-enablement' by default,
> but I am NOT. There is HOMEWORK involved here and most users will get
> into deep tapioca unless they understand all the (ongoing) issues.
>
>> it is also very arguable that we should leave it off.
>
> Yes, it is.
>
>> I think others have argued well to enable it by default.
>
> Disagree. I haven't seen the 'good' argument for 'auto-enablement' yet.
>
> Some of the reasons to NOT 'go there' are coming out in other
> similar threads right now...
>
> Here's a clip from the (concurrent) message thread entitled...
>
> 'Canned deflate conf in manual - time to drop the NS4/Vary'
>
> [snip]
>
> Don't forget the ongoing issue that if you ONLY vary on 'Accept-Encoding'
> then almost ALL browsers will then refuse to cache a response entity LOCALLY
> and the pain factor moves directly to the Proxy/Content Server(s).

I don't think this is true for browsers in use today. Firefox will
certainly cache responses with Vary: Accept-Encoding. Eric Lawrence of
the Internet Explorer team has a nice blog post that explains that in
IE6 and later, Vary: Accept-Encoding are cached:
http://blogs.msdn.com/b/ieinternals/archive/2009/06/17/vary-header-prevents-caching-in-ie.aspx.

Other variants of Vary do prevent caching in IE but Vary:
Accept-Encoding is safe.

What browsers are you thinking of that will refuse to cache a response
with Vary: Accept-Encoding?

>
> If you vary on 'User-Agent' ( No longer reasonable because of the abuse
> of that header 'out there'? ) then the browsers WILL cache responses
> locally and the pain is reduced at the Proxy/Content server level, but
> pie is not free at a truck stop and there are then OTHER issues to deal
> with.
>
> The OTHER 'ongoing issue' regarding compression is that, to this day,
> it still ONLY works for a limited set of MIME types. The 'Accept-Encoding:
> gzip,deflate'
> header coming from ALL major browser is still mostly a LIE. It would seem
> to indicate that the MIME type doesn't matter and it will 'decode' for ANY
> MIME type but nothing could be further from the truth. There is no browser
> on the
> planet that will 'Accept-Encoding' for ANY/ALL mime type(s).

I don't buy this argument. Browsers support content decoding for all
the common mime types that benefit from content decoding. It is true
that IE6 has bugs but they have been hotfixed. See
http://support.microsoft.com/kb/823386 for an example. This was
hotfixed in 2003. I'm not aware of any browser compatibility issues
with text/* mime types for browsers released after IE6. No doubt there
are some IE6 users without this hotfix that are impacted by this
issue. If there are specific concerns about IE6 users, we can
blacklist that user agent from getting gzipped responses in the
default configuration. Let's not disable gzip compression for the
other 90+% of users that have solid support just because one old
browser has spotty but hotfixed support for it.

>
> If you are going to turn compression ON by default, without the user having
> to
> make any decisions for their particular environment, then part of the
> decision
> for the default config has to be 'Which MIME types?'  text/plain and/or
> text/html only? SOME browsers can 'Accept-Encoding' on the ever-increasing
> .js Javascript backloads but some CANNOT.

I assume you're referring to IE6 here.

I don't think the list of typically compressed mime types would
generate much debate, but I could be wrong. text/html, text/css,
text/plain, application/x-javascript and a few others should be
sufficient.

>
> These 2 issues alone are probably enough to justify keeping compression
> OFF by default. A lot of people that use Apache won't even be able to get
> their heads around either one of these 'issues' and they really SHOULD
> do a little homework before turning it ON.
>
> Someone already quoted that...
>
> 'people expect the default config to just WORK without major issues'.
>
> That's exactly what you have now.
> It's not 'broken'.
> Why change it?
>
> Kevin Kiley
>
> [snip]
>
>
>
> -----Original Message-----
> From: Greg Stein <gstein@gmail.com>
> To: dev@httpd.apache.org
> Sent: Tue, Jun 1, 2010 7:40 am
> Subject: Re: Fast by default
>
> Geez, Eric. No wonder people don't want to contribute to httpd, when they
> run into an attitude like yours. That dismissiveness makes me embarressed
> for our community.
> There is zero reason for us to avoid putting deflate into the default
> configuration.
> It is also very arguable that we should leave it off. I think others have
> argued well to enable it by default, while you've simply dismissed them with
> your holier-than-thou attitude and lack of any solid rationale.
> -g
>
> On May 31, 2010 8:06 PM, "Eric Covener" <covener@gmail.com> wrote:
>
> On Mon, May 31, 2010 at 8:30 PM, Bryan McQuade <bmcquade@google.com> wrote:
>> I propose providing an...
> An additional httpd.conf doesn't sound valuable to me.  What slice of
> non-savvy users would scrutinize an alternate config file, can replace
> the config file of their webserver, isn't using a webserver packaged
> by their OS, and wouldn't have just gotten the same information today
> from the manual and 400,000 other websites?
>
> There's currently no <ifModule> bloat in the default conf, but you're
> welcome to submit a patch that adds one for deflate or expires (latter
> seems more unwise to me). See the "supplemental configuration" section
> of the generated config.
>
> This doesn't address mass-vhost companies failing to allow deflate
> because it's not in the no-args HTTPD ./configure , which sounds
> far-fetched to me.  I can't recall a users@ or #httpd user implying
> being subjected to such a thing with their own build or with cheap
> hosting.
>
> --
> Eric Covener
> covener@gmail.com

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