MySQL Troubleshooting

Testing

After you develop a hypothesis about what is going on and how to solve your problem, test the hypothesis and consider your results.

In my job, I meet users who are afraid of testing. There are two main reasons that people reject it: overconfidence (the user thinks that a correct guess does not require testing) and diffidence (the user is afraid of breaking something else).

But even very experienced users make mistakes, so it is risky to just rely on a guess. Always check the result of any change you make. What is quickly noticed can be quickly fixed.

Don’t be shy! Just consider this: if you need to troubleshoot something, you are already experiencing a problem. If one or another test makes the problem worse, at least the test spares you from making a major change that would take even longer to fix. A mistake made during a test can be rolled back in a few seconds.

Further, discovering that a guess is wrong is valuable because you narrow the search area. Fewer options are left, so there’s more chance that your next test will prove correct.

If you don’t want to take any risk of harming your production setup, test in a sandbox. I recommend this especially when a test can change data, but it’s also useful when you simply need to modify some configuration option. Just create a repeatable test case and run it in the sandbox.

And don’t be lazy! Laziness can be a good thing when you are finding the best and shortest way to solve a problem, but it can play a bad joke on you when testing. ...