301 not being cached

[Damon Green <damon.ft@xxxxxxxxx>]

Hi Folks, 

I have an issue with mod_cache, it refuses to cache redirects (301) and insists on cacheing 404 error responses, so really two issues.

I'm using Apache 2.2.17 and the mod_cache/mod_disk_cache from Apache 2.3 which serves stale content from its disk cache when the Tomcat is unavailable. (patched version from the devs)

Trawling the list archives and docos imply that 404 responses should not be cached, and that 30x responses should be, but the behaviour I'm seeing is the opposite of that.

I need 301 redirects to remain working (from the cache) when we disable Tomcat.

To test this Ive created a rewrite rule in the Apache conf:

RewriteRule ^/damon/(.*)    http://www.slashdot.org [R=301,L]

Then cleared the cache, hit a page in /damon/, got redirected, nothing created in the disk cache.

any 200 or 404 however creates files in the cache. 

http://httpd.apache.org/docs/2.2/caching.html

# The response must have a HTTP status code of 200, 203, 300, 301 or 410.

This is largely a function 13.4 in the RFC:

   A response received with a status code of 200, 203, 206, 300, 301 or

   410 MAY be stored by a cache and used in reply to a subsequent

   request, subject to the expiration mechanism, unless a cache-control

   directive prohibits caching. However, a cache that does not support

   the Range and Content-Range headers MUST NOT cache 206 (Partial

   Content) responses.

Any advice or ideas gratefully received.

Regards, 

Damon Green.

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