There are zero FEC puns in this post, against my better judgement. Jeff Dean and Luiz Barroso’s paper The Tail At Scale popularized an idea they called hedging, simply sending the same request to multiple places and using the first one to return. That can be done immediately, or after some delay: One such approach is to defer sending a secondary request until the first request has been outstanding for more than the 95th-percentile expected latency for this class of requests. Smart stuff, and has...