Friday April 29, 2005

My "zone buddy" is cranking away with his J2EE class. I think zones are beating his expectations. He is currently running 14 zones on his server, generally speaking one for each student team (and one for himself and his TA). Running in each zone is GlueCode Joe to get the runtime down to one JVM per zone. It is going to take a bit more time to learn student usage patterns. Student coding patterns is an entirely different topic. Each student gets root access to the zone. If they screw it up, the instructor can remotely create another one. Not a big deal. It's called the "zone lizard-tail" pattern.

I am trying to stay abreast of this student zone endeavor to get a feel for how well this works in practice. The big test will most likely be the last week of the project due date. That's where the drunken student pattern gets replaced by the caffeinated student pattern. That's peak usage time, my friends. All of those active JVM's must get squeezed into 2GB of RAM. Then again, what's the alternative? 14 servers? He's doing it with a single server so far. That's the "clowns in a server" pattern (modeled after the clowns-in-a-volkswagen pattern). This pattern is also known as the ROA (Return on Assets) pattern.

Today I pointed my buddy to the pre-installed MySQL bits in /usr/sfw for one of the projects. /usr/sfw is not exactly intuitive for someone new to (or been away from) Solaris. What's nice about zones is that MySQL can be installed once and "mysqld_safe --datadir path_to_database" will point to the database content in the local zone. This is the "reverse branch office" pattern, where the data is local and the bits are centralized.

When class is over, he can either rebuild the server (the "Rebuild Host" Anti-pattern), or simply delete the existing zones and build new zones for the next class. That's the "replenishing zone" pattern.

Time for the "get back to work" pattern.