openstack team mailing list archive

[Michael Barton <mike-launchpad@xxxxxxxxxxxxxxxx>]

On Tue, Dec 13, 2011 at 9:21 PM, Huang Zhiteng <winston.d@xxxxxxxxx> wrote:
> Can anyone explain why Swift doesn't want to utilize page cache _at all_?

It's an artifact of the use case swift was built for - heavy on
writes, and repeat reads (where a cache would help) are very rare.
Having that memory available to cache dirents and inodes has a
positive impact on performance, since a swift object server has so
many files.

The object server used to not drop caches if the file was small and
the user wasn't authenticated, but I guess that's been factored out at
some point.  It'd be nice to have that logic pluggable or configurable
somehow, since it does make swift kind of useless for things it'd
otherwise be good at, like serving static files directly to browsers.

- Mike