Release It!, 2nd Edition

Extending Your Life Span

The major dangers to your system’s longevity are memory leaks and data growth. Both kinds of sludge will kill your system in production. Both are rarely caught during testing.

Testing makes problems visible so you can fix them. Following Murphy’s Law, whatever you do not test against will happen. Therefore, if you do not test for crashes right after midnight or out-of-memory errors in the application’s forty-ninth hour of uptime, those crashes will happen. If you do not test for memory leaks that show up only after seven days, you will have memory leaks after seven days.

The trouble is that applications never run long enough in the development environment to reveal their longevity bugs. How long do you usually keep ...