PERFORMANCE OF OBJECT STORAGE SYSTEMS

• US 20170371558A1
• Filed: 06/24/2016
• Published: 12/28/2017
• Est. Priority Date: 06/24/2016
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: George, Johnu, Zhang, Kai, Tarre, Marc Solanas, Dutta, Debojyoti, Sharma, Manoj
• Granted Patent: US 10,664,169 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

Approaches are disclosed for improving performance of logical disks. A logical disk can comprise several storage devices. In an object storage system (OSS), when a logical disk stores a file, fragments of the file are stored distributed across the storage devices. Each of the fragments of the file is asymmetrically stored in (write) and retrieved from (read) the storage devices. The performance of the logical disk is improved by reconfiguring one or more of the storage devices based on an influence that each of the storage devices has on performance of the logical disk and the asymmetric read and write operations of each of the storage devices. For example, latency of the logical disk can be reduced by reconfiguring one or more of the plurality of storage disks based on a proportion of the latency of the logical device that is attributable to each of the plurality of storage devices.

Claims

1. A method comprising:

storing a file in a logical disk, wherein fragments of the file are stored distributed across a plurality of storage devices comprising the logical disk and each of the fragments of the file is asymmetrically stored in and retrieved from the plurality of storage devices; and

reducing the latency of the logical disk based on the asymmetrical storage in and retrieval from the plurality of storage devices by;

calculating, for each of the plurality of storage devices, at least one impact factor that identifies a proportion of the fragments stored in or retrieved from each of the plurality of storage devices relative to others of the plurality of storage devices based on the asymmetrical storage in and retrieval from each of the plurality of storage devices;

calculating a proportion of a latency of the logical device that is attributable to each of the plurality of storage devices based, at least in part, on the at least one impact factor and a latency of each of the plurality of storage devices; and

reconfiguring one or more of the plurality of storage disks based on the proportion of the latency of the logical device that is attributable to each of the plurality of storage devices.

2. The method of claim 1, wherein the reconfiguring one or more of the plurality of storage disks based on the proportion of the latency of the logical device that is attributable to each of the plurality of storage devices comprises:

determining which of the plurality of storage devices is a storage device for removal from the logical disk the based on the proportion of the latency of the logical device that is attributable to the storage device; and

removing the storage device from the logical disk.

3. The method of claim 2, wherein the removing the storage device from the logical disk comprises:

transferring data from the storage device to others of the plurality of storage devices by pseudo-randomly distributing from the storage device to the others of the storage devices all fragments associated with files stored in the logical disk;

disassociating the storage device from the logical disk; and

deleting, from the storage device, all the fragments associated with files stored in the logical disk.

4. The method of claim 1, wherein the reconfiguring one or more of the plurality of storage disks based on the proportion of the latency of the logical device that is attributable to each of the plurality of storage devices comprises:

associating a new storage device to the plurality of storage devices comprising the logical disk; and

transferring data from others of the plurality of storage devices to the new storage device by pseudo-randomly distributing from the others of the plurality of storage devices a portion of fragments associated with files stored in the logical disk.

5. The method of claim 2, wherein the proportion for the storage device is larger than the proportion for others of the plurality of storage devices

6. The method of claim 1, wherein the at least one impact factor for each of the plurality of storage devices corresponds to an influence that a corresponding storage device has on the latency of the logical device.

7. The method of claim 1, wherein the each of the fragments of the file being asymmetrically stored in and retrieved from the plurality of storage devices comprises the logical drive accessing the plurality of storage devices a different number of times for retrieving each of the fragments than for writing each of the fragments.

8. The method of claim 1, wherein the each of the fragments of the file being asymmetrically stored in and retrieved from the plurality of storage devices comprises:

writing, by the logical drive, a fragment to a primary storage device and to each of one or more replica storage device of the plurality of storage devices; and

retrieving, by the logical drive, a fragment from the primary storage device and not from the one or more replica storage device.

9. The method of claim 8, wherein storing the file in the logical disk comprises:

storing, by a processor associated with the logical disk, the file to the logical disk by;

parsing objects from the file, the objects being the fragments of the file, and

writing each of the objects to a corresponding primary storage device and one or more corresponding replica storage device of the plurality of storage devices; and

reading, by the processor associated with the logical disk, the file from the logical disk by;

identifying the objects that comprise the file, and

retrieving each of the objects from the corresponding primary storage device and not from the one or more corresponding replica storage device.

10. The method of claim 8, wherein the at least one impact factor for each of the plurality of storage devices comprises:

a read impact factor identifying a first number of fragments for which each of the plurality of storage devices is a primary storage device; and

a write impact factor identifying a sum of the first number of fragments and a second number of fragments for which each of the plurality of storage devices is a replica storage device.

11. The method of claim 10, wherein the calculating the proportion of latency of the logical device that is attributable to each of the plurality of storage devices based, at least in part, on the asymmetrically storage and retrieval of fragments in each of the plurality of storage devices comprises:

retrieving, from each of the plurality of storage devices, the latency of input/output (“

I/O”

) operations measured during a window of time,

determining a weighting factor for each of the plurality of storage devices based, at least in part, on the at least one impact factor; and

determining a weighted latency for each of the plurality of storage devices based on the latency of the I/O operations and the weighting factor by multiplying the latency of the I/O operations by the weighting factor.

12. The method of claim 11, further comprising:

calculating a latency of the logical disk by summing the weighted latency for each of the plurality of storage devices.

13. A system comprising:

a logical disk configured to store a file, wherein fragments of the file are stored distributed across a plurality of storage devices comprising the logical disk and each of the fragments of the file is asymmetrically stored in and retrieved from the plurality of storage devices; and

a network element configured to reduce the latency of the logical disk based on the asymmetrical storage in and retrieval from the plurality of storage devices by;

calculating, for each of the plurality of storage devices, at least one impact factor that identifies a proportion of the fragments stored in or retrieved from each of the plurality of storage devices relative to others of the plurality of storage devices based on the asymmetrical storage in and retrieval from each of the plurality of storage devices;

calculating a proportion of a latency of the logical device that is attributable to each of the plurality of storage devices based, at least in part, on the at least one impact factor and a latency of each of the plurality of storage devices; and

reconfiguring one or more of the plurality of storage disks based on the proportion of the latency of the logical device that is attributable to each of the plurality of storage devices.

14. The system of claim 13, wherein the each of the fragments of the file being asymmetrically stored in and retrieved from the plurality of storage devices comprises:

writing, by the logical drive, a fragment to a primary storage device and to each of one or more replica storage device of the plurality of storage devices; and

retrieving, by the logical drive, a fragment from the primary storage device and not from the one or more replica storage device.

15. The system of claim 14, wherein the at least one impact factor for each of the plurality of storage devices comprises:

a read impact factor identifying a first number of fragments for which each of the plurality of storage devices is a primary storage device; and

a write impact factor identifying a sum of the first number of fragments and a second number of fragments for which each of the plurality of storage devices is a replica storage device.

16. The system of claim 15, wherein the calculating the proportion of latency of the logical device that is attributable to each of the plurality of storage devices based, at least in part, on the asymmetrically storage and retrieval of fragments in each of the plurality of storage devices comprises:

retrieving, from each of the plurality of storage devices, the latency of input/output (“

I/O”

) operations measured during a window of time,

determining a weighting factor for each of the plurality of storage devices based, at least in part, on the at least one impact factor; and

determining a weighted latency for each of the plurality of storage devices based on the latency of the I/O operations and the weighting factor by multiplying the latency of the I/O operations by the weighting factor.

17. A computer-readable non-transitory medium comprising instructions, that when executed by at least one processor configure the at least one processor to perform operations comprising:

storing a file in a logical disk, wherein fragments of the file are stored distributed across a plurality of storage devices comprising the logical disk and each of the fragments of the file is asymmetrically stored in and retrieved from the plurality of storage devices; and

reducing the latency of the logical disk based on the asymmetrical storage in and retrieval from the plurality of storage devices by;

calculating, for each of the plurality of storage devices, at least one impact factor that identifies a proportion of the fragments stored in or retrieved from each of the plurality of storage devices relative to others of the plurality of storage devices based on the asymmetrical storage in and retrieval from each of the plurality of storage devices;

calculating a proportion of a latency of the logical device that is attributable to each of the plurality of storage devices based, at least in part, on the at least one impact factor and a latency of each of the plurality of storage devices; and

reconfiguring one or more of the plurality of storage disks based on the proportion of the latency of the logical device that is attributable to each of the plurality of storage devices.

18. The computer-readable non-transitory medium of claim 17, wherein the each of the fragments of the file being asymmetrically stored in and retrieved from the plurality of storage devices comprises:

writing, by the logical drive, a fragment to a primary storage device and to each of one or more replica storage device of the plurality of storage devices; and

retrieving, by the logical drive, a fragment from the primary storage device and not from the one or more replica storage device.

19. The computer-readable non-transitory medium of claim 18, wherein the at least one impact factor for each of the plurality of storage devices comprises:

a read impact factor identifying a first number of fragments for which each of the plurality of storage devices is a primary storage device; and

a write impact factor identifying a sum of the first number of fragments and a second number of fragments for which each of the plurality of storage devices is a replica storage device.

20. The computer-readable non-transitory medium of claim 19, wherein the calculating the proportion of latency of the logical device that is attributable to each of the plurality of storage devices based, at least in part, on the asymmetrically storage and retrieval of fragments in each of the plurality of storage devices comprises:

retrieving, from each of the plurality of storage devices, the latency of input/output (“

I/O”

) operations measured during a window of time,

determining a weighting factor for each of the plurality of storage devices based, at least in part, on the at least one impact factor; and

determining a weighted latency for each of the plurality of storage devices based on the latency of the I/O operations and the weighting factor by multiplying the latency of the I/O operations by the weighting factor.