On Feb 2, 2008 1:03 PM, Howard Chu <firstname.lastname@example.org> wrote:
> Very good point about these opposing factors. So I figure OpenLDAP just
> uses the cache in the underlying B-Tree instead of managing some kind of
> separate entry cache?
No, we have a separate entry cache too. I originally wrote back-bdb without
any entry caching, but Jong @ IBM benchmarked/profiled it and implemented an
entry cache for it before 2.1 was released. (Back then I was happy just to get
it working, at speeds comparable to back-ldbm. How things change ;)
The motivation here is that the serialized data that we store in the database
is not directly usable with our in-memory data structures. As such, even when
the B-Tree cache is 100% effective, there's a cost associated with
deserialization that we can avoid by using our own entry cache.
There are plenty of interesting data structures/system architectures to
explore, and now you've got the lab resources to try them out.
> > Yeah they're great ideas. We just need to have a solid SLAMD lab and
> > start testing these ideas out. I got the machines:
> > 9 load injectos
> > 1 SLAMD Server
> > 1 beefy server for running ApacheDS>