Adaptive data throttling for storage controllers

Abstract

A method for minimizing latency of data transfer between the redundant storage controllers in a network-based storage controller system that utilizes adaptive data throttling. Each redundant storage controller monitors latency for round trip communications between the redundant controllers by calculating a time required to mirror a write to the other controller and receive a write acknowledge. An average latency for round trip communications between the redundant controllers during a fixed monitoring period is calculated, and at the end of each fixed monitoring period, the average latency is compared to a fixed latency to access the average time latency for mirroring writes is good, acceptable or unacceptable. If the average time latency is good, the one controller reduces or disables throttling for data transfers between the one controller and the server, and between the one controller and back-end storage, increasing a number of this type of data transfer that can be executed in parallel. If the average time latency is acceptable, the one controller does not adjust throttling for data transfers between the one controller and the server, and between the one controller and back-end storage. If the average time latency is unacceptable, the one controller increases data throttling for data transfers between the one controller and the server, and between the controller and the back-end storage, decreasing a number of this type of data transfer that can be executed in parallel.