linuxjournal article on memcached

Perrin Harkins
Fri, 16 Jul 2004 14:57:55 -0400

On Fri, 2004-07-16 at 14:13, Brad Fitzpatrick wrote:
> So say the application NEEDS to do a delete, otherwise the cache would be
> out of sync with the database.  But the memcached's network is unplugged,
> so the delete can't happen.  Then, the client tells one of the multiple
> bucket managers, "Yo, I couldn't fix up bucket 387, so next time you see
> it, wipe the entire bucket, and assign that bucket to another host and
> give me the list of who owns that bucket now."

When I've worked on distributed caches in the past, we always just wiped
any cache server that was off-line for any period of time in order to
prevent it from serving stale data when it comes back up.  It means you
have to rebuild some cache entries, but it's simple and safe.  However,
it does assume you actually know about it when this happens.  If you
frequently have transient network problems, you would need something
like the approach you're describing here.

- Perrin