Seen databases

[Bron Gondwana]

On Tue, 04 May 2010 15:59 -0400, "Ken Murchison" <murch at andrew.cmu.edu> wrote:
> I've been thinking about this for a while and I keep coming back to the 
> same answer.
> 
> seen_local is legacy and I wouldn't expect to find this in the wild 
> anymore.  I don't think we should waste cycles doing anything with it.

Besides - the seen_db code can actually read seen_local files and auto-upgrade
them, so it doesn't hurt too much to remove seen_local and FORCE seen_db.

> I don't recall why seen_bigdb was created by one of my predecesors, but 
> its not used in production at CMU.  I don't think its the way to go, 
> even with your Seen state changes.

I'm tempted to remove it then: simplify, simplify!

> The reason is that I think the distributed Seen state offered by seen_db 
> is the best for sites with a large number of shared mailboxes, such as 
> CMU.  We currently have over 14,000 shared mailboxes that are called 
> bulletin boards on campus (used to be a lot more when we also had 
> non-binary newsgroups).  And we have 10's of thousands of users reading 
> these mailboxes and maintaining their own Seen state.  Using the current 
> divide and conquer approach where we keep each user's Seen state in a 
> separate database seems the most sane to me, rather than having several 
> hundred or thousand handles open to a single database.

I'm sold.

> Any change that will effect the performance or stability of CMU's 
> current environment would not be a good thing.

For sure :)

I've actually already made the changes I need to seen_db and not to
seen_bigdb, so I'm happy anyway!

Bron.
-- 
  Bron Gondwana
  brong at fastmail.fm