Napkin Estimates

Equations

Throughput

$$\begin{array}{r}\text{RWRatio}=5\\ {\text{AvgRequestSize}}_{\mathrm{read}}=50\mathrm{Kb}\\ {\text{AvgRequestSize}}_{\mathrm{write}}=50\mathrm{Kb}\\ \\ \\ {\text{RPS}}_{\mathrm{i}}=\text{DAU}\times \text{RWRatio}÷86,400\\ {\text{Throughput}}_{\mathrm{i}}={\text{RPS}}_{\mathrm{i}}\times {\text{AvgRequestSize}}_{\mathrm{i}}\\ {\text{QPS}}_{\mathrm{n}}=\text{RPS}\times \text{QueriesPerRequest}\end{array}$$