Great to see this post here -- really enjoyed writing it! I think it's really cool how an algorithm from an operational research context can play a critical role in a high-availability large-scale cloud service.
sumtechguy · 21m ago
LP is a shockingly good way to optimize a system. If you can put inputs/outputs into the correct form. Had an econ prof that loved these things for doing supply/demand maxima and minimum finding. He didnt outright say it but I think it was his current line of study when I was taking classes from him the 90s. I thought that, as he managed to bring it up in every class he taught.
ayhanfuat · 28m ago
> X = [x1, ..., Xn]: instances of each type to launch
Is this a continuous variable? Seems discrete to me. I am surprised it is solved by simplex.
Frummy · 19m ago
It's the answer, a vector of integers
ayhanfuat · 13m ago
Simplex cannot give a vector of integers though, unless the constraint matrix is unimodular. Maybe the integrality constraint was relaxed.
cweld510 · 6m ago
You're right -- we do relax the integrality constraint, gaining performance at the expense of some precision, and we're generally able to paper over the difference at scheduling time. We've investigated integer linear programming for some use cases, but for solves to run quickly, we have to constrain the inputs significantly.
Is this a continuous variable? Seems discrete to me. I am surprised it is solved by simplex.