What are some good ways to test pt-online-schema-change before using it on a production database? I have already tried the tool on a dump of the production database and it has worked well but the production database experiences a lot of traffic and I want to do a more thorough test of the tool to see if there will be any issues. One idea that came to mind was to test the tool on a real time replica of the production database but I am not sure how feasible that is and I’d love to hear your thoughts on this. Thank you!