Loggerhead reviews + broad plan

[Max Kanat-Alexander]

On 04/08/2010 04:05 AM, Ian Clatworthy wrote:
> I've made some good progress this week getting my head around the
> Loggerhead code base and base technologies, WSGI/Paste and ZPT. I'm
> hoping to start reviewing and landing the numerous outstanding patches
> next week, if others don't beat me to them. :-)

	That's awesome! :-)

> Chameleon is a faster implementation of ZPT than simpleTAL, as
> illustrated by Kapil's branch porting Loggerhead to it. Together with
> some more intelligent caching of the revision graph that John is working
> on, I'm hoping Loggerhead 2.0  + bzr 2.2 will be notably faster than
> Loggerhead 1.17 + bzr 2.1.

	Is the Chamelon port going to be a significant amount of effort (will
the templates themselves have to change extensively), or is it just a
swap-out?

	I'm asking because ultimately, it seems like the only way that
loggerhead is going to operate at Launchpad scale would be to scale
horizontally (across machines). That is, I don't know that it matters so
much that we spend a lot of programmer time on making it fast on one
machine, when we could instead be buying cheap hardware if we had
horizontal scaling.

	Also, what's the caching change that John is working on? mwhudson and I
have had some pretty extensive discussions about the revision graph
cache, so it's possible we could be helpful there. (Although maybe
mwhudson has already done all this, and I just have no idea. :-) )

	-Max
-- 
Max Kanat-Alexander
Chief Engineer
http://www.everythingsolved.com/
Everything Solved: Complete Computer Management