Predictable Answers Depend on Unpredictable Latencies

In the eighties, wewe were supporting a bank. Andiwas this back in the block mode terminal days. We instrumented it so that it would take three seconds between when you pushed enter and when you got the answer. That was extremely popular with human beings. People tend to like predictable behavior. It turns out that if i want to make sure that this change exactly captures all the linearisable history, sometimes that will get slow. Or we can build a system that will always show you the last thing which has been changed. But those are business decisions in designing a system. Do you want it right or do you want itright now? Usually, usually, humansUsually, they