Usually requests to a server are not periodic, there is no period. They are random and follow something like the Poisson distribution.
Requests per seconds is as SI as it gets since the second is the base SI unit for time.
In "stable conditions":
* The number of requests in a given time interval will follow a poisson distribution.
* The times of requests will be uniformly distributed
* the duration between two consecutive requests will be exponentially distributed.
Usually requests to a server are not periodic, there is no period. They are random and follow something like the Poisson distribution.
Requests per seconds is as SI as it gets since the second is the base SI unit for time.