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Here's the slides from the user centric identity tutorial that I gave this afternoon. The PDF won't show the embedded screencasts. I've included them separately. Here's one on using CardSpace and one on using OpenID. If you're interested in getting my Perl wrappers for using the JanRain OpenID libraries and the guestbook application, contact me.
Lamont Peterson, co-founder of NeverBlock is talking about XEN and virtualization.
The talk is an intro to virtualization technology and a discussion of why use virtualization. Here are some pros:
Of course, there are some cons:
It's a good idea to keep some headroom on each machine so that VMs can be migrated when a physical box dies. This gets easier (and less costly) as the number of physical boxes you're using grows. Here's my analysis: The headroom you need is somewhat greater (20%) than 1/N where N is the number of servers. So with 2 boxes, you can use about 40% of each machine and still be able to migrate everything from one machine to the other in the case of problems. With 10 boxes, you can load boxes up to 80% (as much as I'd do in any event) and still have room to migrate a single bad server's VMs. XEN supports live migration if you get the storage architecture right.
Tags: virtualization open+source utosc uosc07
I'm in Brad Nicholes' session on configuring Apache 2.2.
First up he starts talking about MPM (multi-processor modules). MPMs control the multi-processing that happens on in Apache (servers and threads). If you install Apache, the default is the pre-fork MPM that doesn't include threads. You have to install the Worker MPM to get threads. the pre-fork MPM is more stable, but slower. The Worker MPM won't play well with mod_perl and other modules that aren't thread friendly.
Brad recommends using include files to modularize configuration. I've never done this (habit) preferring to have everything in one place so I don't have to go out and look in multiple files. Still I can see the wisdom in this. Sometimes the configuration file can get pretty hairy.
Huh, I didn't know you could use ServerAlias (with or without wildcards) to create aliases for a host. That will save me a few lines in my configuration file!
LDAP authentication looks relatively easy to set up. This would be good to use on my server at BYU since we have an LDAP server anyway for the lab. I've never bothered to figure it out. Brad makes it look easy enough to try.
Tags: open+source apache utosc uosc07
Several people asked for a copy of my slides from keynote this morning. Here they are: Longtails and Software.