Quality of Service Implementation in a Networked Storage System with Hierarchical Schedulers

摘要

Methods, systems, and computer programs are presented for allocating CPU cycles in a storage system. One method includes operations for receiving requests to be processed, and for associating each request to one task. A foreground task is for processing input/output requests, and the foreground task includes one or more flows. Each flow is associated with a queue and a flow counter value, where each queue is configured to hold requests. The method further includes an operation for selecting one task for processing by the CPU based on an examination of the number of cycles processed by the CPU for each task. When the selected task is the foreground task, the flow having the lowest flow counter is selected. The CPU processes a request from the queue of the selected flow, and the flow counter of the selected flow is increased based on the data consumption of the processed task.

主权项

1. A method for allocating cycles of a CPU (central processing unit) of a storage system, comprising:
receiving a plurality of requests to be processed by the CPU; associating each request to one of a plurality of tasks, a first task of the plurality of tasks being for processing input/output (IO) requests of the storage system, the first task including a plurality of flows and each flow being associated with a queue and a flow counter value, each queue being configured to hold requests; selecting one of the plurality of tasks for processing by the CPU based on an examination of a number of cycles processed by the CPU for each task of the plurality of tasks that requires processing; when the selected task is the first task, selecting one of the plurality of flows having a lowest flow counter value among the flow counter values of flows that require processing by the CPU; and processing by the CPU a request from the queue of the selected flow, the flow counter of the selected flow being increased based on a data consumption of the processed request.