Differentiated Storage QoS

• US 20110145449A1
• Filed: 12/11/2009
• Published: 06/16/2011
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Inventors: Uysal, Mustafa, Merchant, Arif A.
• Granted Patent: US 9,104,482 B2
• Time in Patent Office: Days
• US Class Current: 710/40
• CPC Class Codes: G06F 11/008 Reliability or availability analysis
• CPC Class Codes: G06F 2209/501 Performance criteria
• CPC Class Codes: G06F 9/5011 the resources being hardware resources other than CPUs, Servers and Terminals

Abstract

A system includes disk storage to provide differentiated storage QoS for a plurality of IO classes. Each IO class has a plurality of applications to it. A QoS controller collects IO statistics for each application and each class. The QoS controller adaptively determines an IO class assignment for each application based at least in part on the collected IO statistics.

Claims

1. A storage system, comprising:

disk storage to provide differentiated storage quality of service (QoS) for a plurality of input/output (IO) classes, each class having a plurality of applications assigned to it;

a QoS controller to collect IO statistics for each application and each class; and

the QoS controller to adaptively determine an IO class assignment for each application based at least in part on the collected IO statistics.

2. The storage system of claim 1, wherein the disk storage further comprises:

a concurrency enforcement module to enforce a concurrency level for outstanding IO requests in each class.

3. The storage system of claim 2, wherein the QoS controller further comprises:

a concurrency determination module to dynamically determine a concurrency level necessary to maintain a desired quality of service for each class.

4. The storage system of claim 3, wherein the concurrency determination module further comprises:

at least a linear regression module or a theoretical queuing module to model a relationship between a priority of an application and the desired quality of service in view of an IO class assignment.

5. The storage system of claim 1, further comprising:

a tagging module to tag IO requests from an application with a class identifier (ID) according to the determined class assignment for the application.

6. The storage system of claim 1, wherein the desired quality of service includes at least one of a desired queuing delay or a desired latency.

7. The storage system of claim 1, wherein the QoS controller further comprises:

a stability module to limit concurrency allocation changes per control cycle.

8. A method, comprising:

dynamically mapping a storage input-output (IO) QoS requirement for an application to one of multiple latency-based IO classes;

adaptively assigning the application to an IO class based on the mapping;

determining an IO concurrency level necessary to achieve a desired QoS for each IO class; and

executing storage IO instructions for the application according to the determined concurrency level for the IO class to which the application is assigned.

9. The method of claim 8, further comprising:

determining that a combined IO concurrency level for multiple IO classes exceeds a total concurrency threshold for a system; and

reducing the concurrency level of at least one IO class.

10. The method of claim 9, wherein the reducing of the concurrency level is performed on a proportional basis for each application assigned to the at least one IO class.

11. The method of claim 9, wherein the reducing of the concurrency level of at least one class further comprises:

reassigning an application from the at least one IO class to a different IO class based on a priority of the application.

12. The method of claim 9, wherein reducing the concurrency level further comprises:

reassigning at least one application to a different IO class.

13. The method of claim 8, wherein adaptively assigning the application to an IO class comprises:

dynamically measuring actual IO throughput for the application;

determining that the actual IO throughput for the application is insufficient; and

reassigning the application to a different IO class.

14. A computer-readable storage medium containing instructions that, when executed, cause a computer to:

aggregate multiple host applications into a single storage input/output (IO) class; and

adaptively provide differentiated storage QoS control per application where disk storage handles differentiated IO scheduling per class.

15. The computer-readable storage medium of claim 14, wherein the instructions that cause the adaptive providing of differentiated storage QoS comprise further instructions that cause the computer to:

tag input/output (IO) requests received from a host with an application identifier (ID);

map the application ID to an IO class; and

assign the tagged IO requests to the IO class to which the application ID is mapped.

16. The computer-readable storage medium of claim 15, wherein the mapping is based on at least one of an application priority or an application throughput requirement.

17. The computer-readable storage medium of claim 15, wherein the instructions that cause the computer to map the application ID to an IO class comprises further instructions that cause the computer to:

build an application model for an application based on collected IO statistics, the model relating application priority and desired quality of service of IO requests;

build a concurrency model based on collected IO statistics to estimate concurrency demand associated with the application if assigned to a particular IO class; and

generate a class assignment for the application based at least in part on the models.

18. The computer-readable storage medium of claim 17, comprising further instructions that cause the computer to:

determine whether a total concurrency threshold is satisfied in response to the generated class assignment; and

reduce the concurrency level of at least one IO class if the total concurrency threshold is not satisfied.

19. The computer-readable storage medium of claim 18, wherein the instructions that cause the computer to reduce the concurrency level of at least one IO class comprise further instructions that cause the computer to:

degrade application performance in inverse proportion to a priority of the application.