On Dec 21, 2009, at 5:58 PM, Hyrum K. Wright wrote:
Personally, I don't like any of them, and am hoping there is still
some way of using Subversion commits to www/. Thoughts?
Some further details might be of interest:
We've just completed applying, as a "hot-fix," several of the changes
that will be coming in the upgrade in January. But not all of them;
for example, a very relevant change coming in January is upgrade of
the platform from Linux 2.4 to 2.6, and that can't be done in a 20-
minute down. We do have one or two sites even larger than Tigris and
running on Linux, and they did see behaviors similar to what happened
today, and they were significantly mitigated (though not wholly fixed)
by the changes we've just made, so we have pretty good confidence the
system will function until the upgrade.
The point I made to Hyrum earlier is that the practice of storing a
large binary file in trunk/www/ (which is then post-commit whisked
into an htdocs/ area for Apache to serve up directly) is a part of the
failure syndrome: many requests for a big file makes for long
transactions makes for overlapping requests makes for more open file
handles into the file system, and thereby hangs the problem. The
kernel update is directly relevant (removes a 256-concurrent-IOs
limit), and so until we have that, I'd like to be careful. Dispensing
the release from "Documents and files" moves it to a different mount
point, pulling from a different pool of 256.
-==-
Jack Repenning
Chief Technology Officer
CollabNet, Inc.
8000 Marina Boulevard, Suite 600
Brisbane, California 94005
office: +1 650.228.2562
twitter: http://twitter.com/jrep
