[Mod_gzip] "mod_gzip_send_vary=Yes" disables caching on IE? (1.3.26.1a)

[Robert Collins]

--=-bnpiKiM+cWyiio3s55PF
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable

On Mon, 2002-12-09 at 19:34, Slava Bizyayev wrote:
>
> Unfortunately, I can not say the same about the pure "Vary: *". In my
> experiment:
>=20
> C05 --> S06 GET /devdoc/Dynagzip/Dynagzip.html HTTP/1.1
> C05 --> S06 Accept: */*
> C05 --> S06 Accept-Language: en-us
> C05 --> S06 Accept-Encoding: gzip, deflate
> C05 --> S06 User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows 98)
> C05 --> S06 Host: devl4.outlook.net
> C05 --> S06 Accept-Charset: ISO-8859-1
> =3D=3D Body was 0 bytes =3D=3D
>=20
> C05 <-- S06 HTTP/1.1 200 OK
> C05 <-- S06 Date: Mon, 09 Dec 2002 05:53:09 GMT
> C05 <-- S06 Server: Apache/1.3.22 (Unix) Debian GNU/Linux mod_perl/1.26
> C05 <-- S06 X-Module-Sender: Apache::Dynagzip
> C05 <-- S06 Expires: Monday, 09-December-2002 06:23:09 GMT
> C05 <-- S06 Content-Type: text/html; charset=3Diso-8859-1
> C05 <-- S06 Content-Length: 51665
> C05 <-- S06 Vary: *
> =3D=3D Body was 51665 bytes =3D=3D
>=20
> My browser generates the same (unconditional) request every time when I t=
ry
> to reach the same URL.
>=20
> So, it seems more safe to use "Vary: User-Agent,*" instead of just "Vary:=
 *"
> for uncompressed content even if there are no User-Agent features in your
> response...

'Vary: *' is MEANT to generate requests every time, to validate the
object by ETAG.

I quote from rfc 2616, 13.6 'caching negotiated responses':
   A Vary header field-value of "*" always fails to match and subsequent
   requests on that resource can only be properly interpreted by the
   origin server.

Note that this section applies to ALL caches - shared ones such as
squid, and private ones such as IE's temporary internet files.

Cheers,
Rob



--=-bnpiKiM+cWyiio3s55PF
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)

iD8DBQA99H1qI5+kQ8LJcoIRAoROAKCcrV1LarA4eL8+mMHFbkp5WSTQVwCgtrSN
TkvMrzA2z1g0Wi2FzuoPwQk=
=3RLZ
-----END PGP SIGNATURE-----

--=-bnpiKiM+cWyiio3s55PF--