wiki madness

Toshio Kuratomi a.badger at gmail.com
Fri Nov 2 18:06:11 UTC 2007


Chuck Anderson wrote:

> Won't there be performance problems with a TurboGears-based wiki?  I 
> thought MirrorManager was having issues with TG performance and had to 
> enable form-data caching to get acceptable performance at the cost of 
> possibly stale data.  I don't know the details behind it, but that was 
> the reason I was given for why when you edit forms in MM it sometimes 
> returns old pre-edit field values.
> 
We might have performance issues but I'm confident they'll be different 
performance issues than we're currently experiencing ;-)

The issues we're running into with moin right now are largely caused by 
Moin's philosophy of having to run off the filesystem, not a db.  This 
means 1) we're unable to spread the load among multiple different app 
servers so we are constrained to a single server's memory and CPU 
resources, 2) it makes multiple views of data much harder than it needs 
to (in the subscription list case, Moin has to walk the filesystem, 
finding each user's prefs file, parsing it for a watchlist, if the 
watchlist exists, checking if the page and page categories are in that 
watchlist, and finally being able to send the notification.  With a db, 
we'd have a separate table for the watchlist and have indexes for the 
userid and the pagename.  Searching for a page wouldn't have to open a 
file for every single one of our users, instead it would access a single 
table and pull out the users which were in the watchlist.)

With MirrorManager I know we've had memory and db query speed issues 
trying to serve the mirrorlist directly from the TG app.  I wasn't aware 
that mirrormanager was having trouble keeping up with it's management 
functionality, Matt is that still true or is caching a leftover from 
when the two functions were combined?  I don't think the wiki is as busy 
as mirrormanager's mirrorlist serving but it would definitely be busier 
than any of our other apps.  We'd have to take a close look at this to 
see where we're bottlenecking in currently deployed code before deciding 
if we want to migrate.

-Toshio




More information about the Fedora-infrastructure-list mailing list