Before we jump to how, I’d better spend some words on why a real-time replay is needed.
The main reason is the complexity involved in capturing and analyzing a workload for extended periods of time. Especially when performing migrations and upgrades, it is crucial to capture the entire business cycle, in order to cover all possible queries issued by the applications. All existing benchmarking tools require to capture the workload to a file before it can be analyzed and/or replayed, but this becomes increasingly complicated when the length of the business cycle grows.
I’m not sure how frequently I’d use real-time replays, but it’s nice to know that it’s pretty easy to pull off with WorkloadTools.