Re: "Squid" failed to cache from FTP sites that does not support RESUME

From: Henrik Nordstrom <hno@dont-contact.us>
Date: Wed, 01 Sep 1999 03:02:55 +0200

Squid does not parse directory listings to find modification times, is
uses the MDTM FTP command and if that fails it relies on refresh_pattern
settings.

The current recommended refresh_pattern settings to allow caching of FTP
objects from servers not supporting MDTM and Gopher objects is:
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440

Squid versions prior to Squid 2.2 got away without this refresh pattern
due to a silly bug where FTP objects was modified "infinitely" ago if
MDTM isn't supported.

FTP and GOPHER are about the only refresh_pattern cases where a min age
>0 is safe and justified.

--
Henrik Nordstrom
Spare time Squid hacker
Dave J Woolley wrote:
> 
> > I think so. I _have_ seen this sort of behaviour before. I can think of
> > three possible causes:
> >
>         I still think that a directory listing format that it
>         can't parse is a real possibility; although I think there
>         are still some Unix ftpd's that don't support the
>         REST <byte-offset> hack, you are more likely to find
>         them on non-Unix systems, either because the system doesn't
>         have the simple Unix model of file structures (VMS?, IBM
>         mainframes) or because the feature was missed out in an
>         attempt to get to market quickly.
> 
>         Unless it can parse the directory listing, it can't
>         get a useable last modified date.
Received on Tue Aug 31 1999 - 19:46:27 MDT

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