Dev::Blog

So as I mentioned earlier, I’ve been using an exercise ball for an office chair since Monday, and it’s been working pretty well. My back is still a bit sore at the end of the day, but it’s getting better, which leads me to think that I’m getting stronger and not just straining something.

More importantly, I’m getting a lot better at sitting relatively still without putting my legs on the floor. I can’t do much while I do this though, so I’m limited to reading a screen or talking to someone, and most of the time I’m busy actually working (blog breaks notwithstanding).

But hey! You know what would have made a good practice time? Waiting for compiles. Remember compiles? Ahh, good times. Curse you, interpreted languages and continuous integration build machines for stealing my quality exercise time!

Now if you’ll excuse me, I’m off to work on my next challenge - no feet on floor while drinking tea.

(P.S.: filed under “load balancing,” natch)

I recently implemented an ASP.NET web farm (i.e. a set of load balanced servers running the same set of applications. This took forever to finally implement due to other priorities, but system stability was starting to suffer, so we went for it. The total process took about a week (at 70% time or so), as we had to retrofit the existing applications. It should take about a month to write it all up, but there’s a handy-dandy category for it should you want to read along.

The biggest complication involved user-uploaded content - we’ve got a few apps with pictures and audio files sent in by users (either the public or administrators). While some of the applications had been designed to put that stuff in the DB, it turns out that web applications use the database quite a bit, and converting the rest of the sites to store data as BLOBs seemed inefficient. We ended up still using the DB server, but as a simple media share using Windows file sharing instead of taxing poor ol’ MySql.

The first thing that had to change was our firewall. For reference, we needed to open tcp ports 135, 137, 139 and 445 between each server, and we also enabled ICMP traffic.

Next up: file permissions, part one of a thousand.