Definition of "throttler"

[…] a crowd of ragged, discharged soldiers, who, having served a government which takes and never gives, returning home without pay, took vengeance on the legalized throttlers of travel and trade.

Missionary Review of the World; 1878-1939 (volume 20, part 2, page 723)

Current Blocked Async I/O Requests is the number of current asynchronous I/O requests blocked by bandwidth throttler.

1996, James J. Townsend, Web Development with Microsoft Resources, page 191