2.7 supports the "stale-if-error" cache-control directive, which will
accomplish this goal. The only caveat (AFAIK) is that it will only
continue to serve objects if origin returns a 500 server error or if
the origin is unreachable; if the origin returns a 404 it will flush
the object and pass the 404 through.
http://tools.ietf.org/html/draft-nottingham-http-stale-if-error-01
-C
On Jan 26, 2009, at 7:52 PM, Tim McNerney wrote:
Is it possible to configure Squid so that if an object becomes stale
and the server tries to fetch a current copy of the object, but the
object/server is unavailable, it will continue serving the cached
version?
If so, what other control can be used in this case? Say you want to
allow it to run an hour over expiration before purging it. Or you
wanted to set how often to retry the source server.
This question is specifically for 2.6, but it would be great to know
if things have changed with newer versions.
Thanks.
--Tim