howdy!
the feeds are really slow, so slow that building a feed often sends the stack into an unrecoverable hang.
i'm not sure why the feeds should be so slow.
most of the feeds we run have only category and/or date parameters, so it should be possible to server this list from the browse cache, using the browse services.
that would remove the necessity of running each article through XACML, which may be one of the bottlenecks.
i'm also pretty sure that all the info necessary to pull for each article exists in the browse cache for the non-extended feed.
the only other parameter (not used at all in the production system) is author. in this case, we'd need to go to mulgara (or lucene!!!) instead of building from browse.