assuredConcurrencyShares (ACS) configures the execution limit, which is a limit on the number of requests of this priority level that may be exeucting at a given time.
ACS must be a positive number.
The server's concurrency limit (SCL) is divided among the concurrency-controlled priority levels in proportion to their assured concurrency shares.
This produces the assured concurrency value (ACV) --- the number of requests that may be executing at a time --- for each such priority level:
LimitedPriorityLevelConfiguration specifies how to handle requests that are subject to limits.