Using psychology to solve problems

Kirk Pepperdine: Yes, I find a lot of performance issues are a reflection of some dysfunctionality within the organization and not really a problem with the people who deployed the tech.

Something has gone wrong at an organizational level and it creeps out somehow into the systems. You actually have to deal with the psychology of the situation.

Sometimes, people get fired, which is never nice. In a couple of cases, I've actually managed to keep people from being fired because I knew they did the right thing, but they just messed up in one really small way. They actually had taken their company three or four steps forwards but their one small mistake took them back one step. Everybody was looking at the one step backwards and not at the fact that they took the company four steps forwards in the process.

Geertjan Wielenga: These are really interesting insights that you have gained from your engagements. How do you feed them into your conference topics as a speaker?

Kirk Pepperdine: I used to talk about the psychology of certain situations, but I stopped because developers are never really interested in that. I talk about tactical hacks and the effect that they can have on the psychology of the situation instead.

The funniest story is one tactical hack I put in. The CEO was talking to me afterwards and asked what I had done. I said, "Well, I have put 13 lines of code in the application to do this really bad thing to the system that makes it run smoothly."

He was shaking his head and he said, "Wow, that's the most expensive 13 lines of code I've ever paid for!" I didn't say anything at the time, but actually the other lines of code that were causing the problem were more expensive!

Geertjan Wielenga: Java performance is what you get engaged in and also what you talk about, but what are some of the specific topics?

Kirk Pepperdine: Garbage collection is the topic that many people are interested in. I keep talking about it all over the place. What makes garbage collection interesting is that it can have a really huge impact on the performance of your application. Just to give you a hint, with one of my clients that I'm currently working with, all I've been doing is tuning garbage collectors. With the first set of tuning that I did, I took the service-level agreement (SLA) violation rate down from 6% to 1% and it was just by tuning the garbage collector.

Geertjan Wielenga: Have you written books or guidelines that collect all these insights about garbage collection, or performance in general, together?

Kirk Pepperdine: I never have. The problem is that the space changes at such a rate that by the time you write anything more than an article, what you've written is obsolete.