I set watching at least one OSDI'20 presentation video per day during the long vacation as one of my plans.
A large scale analysis of hundreds of in-memory cache clusters at Twitter https://www.youtube.com/watch?v=OQtMM5vdhlI&feature=emb_title
The authors traced and analyzed the workloads on the Twitter’s in-memory cache systems. To me, below findings were interesting.
There are many write requests. Size of each object is not so big (median 200 bytes), so metadata, which sizes 64 bytes per each object, is a burden Size of each key is not small compared to the size of each value.