The Value of Adaptivity in LSM Bloom-Filter Tuning: A Log-Law and a Two-Clock Frontier (opens in new tab)

Log-structured merge (LSM) trees attach an approximate-membership filter to every run and must split a fixed memory budget across them. The static optimum is known (Monkey); a large systems literature then makes the allocation adaptive, tracking shifting hotness online. We ask a prior question: when is that adaptivity worth its machinery? We give three analytical answers and validate them on synthetic sweeps, real Twitter production cache traces...