How to Make Things Faster

Chapter 11. But My Whole System Is Slow

Sometimes, when you ask people for a list of symptoms, they’ll answer, “Everything. Literally everything is slow.” No matter whether it’s one specific symptom, or forty-nine, or literally everything, you need a list of symptoms that you can reproduce and diagnose.

Once, a client with an everything-is-slow problem got a little frustrated with my insistence that we identify just one program to start with. I persisted until he finally said, with some exasperation, that even executing a trivial SQL statement to return the system date was slow. “Excellent,” I said, “then let’s trace that!” I know he was thinking the idea was ridiculous, but it was easy to do. He humored me, and he traced it.

The trace immediately revealed a bug. The patch for this bug was already listed in the pile of dozens of recommendations that various people had offered. However, none of those recommendations were scheduled for implementation any time soon, because there’d been no apparent cause-effect linkage between any of the recommendations and the troubles they’d been having. Our trace, of course, was sufficient evidence to escalate the urgency of the patch idea.

I don’t think anyone ever actually told me how many symptoms were relieved by applying the patch. It was almost certainly more than just the one SQL statement that he had traced.