In a simple queue the waiting time grows like 1/(1-ρ), so latency explodes as utilization ρ nears 100%. That is why capacity plans target 50-70%, not 95%.
Utilization
The fraction of time a server is busy: arrival rate divided by service rate.
In a simple queue the waiting time grows like 1/(1-ρ), so latency explodes as utilization ρ nears 100%. That is why capacity plans target 50-70%, not 95%.