Percona Playback is designed to take captured database load in the form of a MySQL slow query log or a tcpdump capture of MySQL protocol traffic and replay that load against a different database server. It can be used to benchmark server options, different MySQL versions or variants and be useful to developers in testing patches to the server that are meant to improve performance.

It's goal is to make it easier to replay load captured from production environments, something which has been tricky in the past. You can also alter how the load is played back: accurate, as fast as possible etc.