Revelations at BSDCan

How the mind works is fascinating.

I have this happen entirely too often. My reflexive assessment is that I'm a relatively smart person, but not a very innovative person.

For example, at Poul-Henning's talk yesterday, he made a comment on how foolish it is to use "round-robin" style dispatching for load balancing. He called it "queue" or FIFO, but they're all similar concepts -- the least recently used system is the next one up for use.

In 99% of the cases, this is the least efficient way to do this. If you're talking about RAM, why not take advantage of the cache and use the most recently used chunk, which is probably already in the cache? If you're talking about load-balancing web servers, the chances are good that the most recently hit web server has the most up to date information, possibly in its memory cache. Why on earth would you want to dispatch the HTTP request to the server that's least likely to have the most updated data in RAM, and is therefore likely to be the slowest to respond and use the most resources to generate the response?

The thing that amazes me about these revelations is that they're obvious! But I never made the connection. This is why I think I'm not very innovated. However, I immediately understood what PHK was getting at, which makes me believe that I'm reasonably smart.

Robert Watson's talk on the new security features in FreeBSD was along a similar vein. I've been trying to understand why one would need mandatory access controls for a few years now, ever since Tom Rhodes introduced me to it a few years ago. I could understand what they did, I just couldn't grok why it was worth writing code for.

Now, after listening to Robert talk, it's not only crystal clear what problem it's intended to solve and how, but I know that it's something I need to implement at work, and I understand that it's the correct tool for the job. Nice.

Why I couldn't work this out on my own is the question that irritates me.

I don't think I'm the only person who does this. I think we've all had the experience of trying to explain something to someone and they just don't get it. It's just irritating to know that occasionally I'm the one who doesn't get it.