Rebalancing operation using a solid state memory device

• US 9,881,039 B2
• Filed: 05/26/2009
• Issued: 01/30/2018
• Est. Priority Date: 05/26/2009
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Stein, Yan Wang, Mulay, Harshwardhan S., Nagpal, Abhinay R., Patil, Sandeep Ramesh
• Primary Examiner(s): Peng, Huawen A
• Application Number:
  US12/472,321
• Publication Number:
  US 20100306288A1
• Time in Patent Office: 3,171 Days
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures

Abstract

Systems and methods to manage database data are provided. A particular method includes automatically identifying a plurality of storage devices. The storage devices include a first device of a first type and a second device of a second type. The first type includes a solid state memory device. The method may further identify a high priority data set of the database. A rebalancing operation is conducted that includes moving the high priority data set to the solid state memory device and substantially evening distribution of other data of the database among the storage devices.

Claims

1. A computer program product comprising a computer readable storage device storing computer readable program code embodied therewith, the computer readable program code comprising program code executable by a computer to:

assign a priority tag to each data item of multiple data items in a database system according to one or more priority assignment rules, the multiple data items including data, the priority tag of each data item classifying the data item as a high priority data item or a low priority data item, wherein data items classified as high priority data items include frequently-accessed data or boot data;

identify each of a plurality of hardware data storage devices in the database system to obtain identified hardware data storage devices, wherein the identified hardware data storage devices include a first hardware data storage device identified as a first type and a second hardware data storage device identified as a second type, wherein the first hardware data storage device comprises a solid state memory and the second hardware data storage device comprises a hard disk memory, and wherein hardware data storage devices of the first type have faster memory access times than hardware data storage devices of the second type; and

in response to one or more rebalancing triggers occurring at least when a storage device is added or deleted from the database system, execute a balancing operation, that includes a first move operation and a second move operation,

wherein, in response to the balancing operation being executed;

the first hardware data storage device has a greater amount of data than the second hardware data storage device, and the first hardware data storage device includes the high priority data items and at least one low priority data item of the low priority data items and the second hardware data storage device includes at least one low priority data item of the low priority data items,

wherein the first move operation is performed to move the high priority data items of the multiple data items to the first hardware data storage device, and

wherein the second move operation is performed to evenly distribute the low priority data items of the multiple data items among the identified hardware data storage devices.

2. The computer program product of claim 1, wherein the second hardware data storage device comprises a hard disk memory.

3. The computer program product of claim 1, wherein the second move operation is performed after the first move operation, and wherein, in response to the balancing operation being executed, the first hardware data storage device includes the high priority data items and at least one low priority data item of the low priority data items.

4. The computer program product of claim 1, wherein the program code is executable by the computer to determine that at least one hardware data storage device has been removed from database use, and wherein a second balancing operation is automatically executed in response to a determination that the at least one hardware data storage device has been removed.

5. The computer program product of claim 1, wherein identification of each of the plurality of hardware data storage devices comprises executing, by the computer, disk detection instructions to query system data structures through an application programing interface of the plurality of hardware data storage devices.

6. The computer program product of claim 1, wherein identification of each of the plurality of hardware data storage devices comprises determining a performance attribute associated with each of the plurality of hardware data storage devices.

7. The computer program product of claim 1, wherein identification of each of the plurality of hardware data storage devices comprises creating a disk topography, and wherein the disk topography includes location data that indicates on which identified data storage device of the plurality of hardware data storage device each data item of the multiple data items is stored.

8. The computer program product of claim 7, wherein the disk topography further includes at least one performance attribute associated with each of the plurality of hardware data storage devices.

9. A method of using a processor to manage a database system, the method comprising:

assigning, according to one or more priority assignment rules, a priority tag to each data item of multiple data items in the database system, the data items including data, the priority tag of each data item classifying the data item as a high priority data item or a low priority data item, wherein data items classified as high priority data items include frequently-accessed data or boot data;

identifying each of a plurality of hardware data storage devices, wherein identified hardware data storage devices include a first hardware data storage device identified as a first type and a second hardware data storage device identified as a second type, wherein hardware data storage devices of the first type are more energy efficient or faster than hardware data storage devices of the second type, wherein the first hardware data storage device comprises a solid state memory and the second hardware data storage device comprises a hard disk memory; and

in response to one or more rebalancing triggers corresponding to when a storage device is added or deleted from the database system, occurring at regular intervals, occurring through manual system administrator input, or a combination thereof, executing a balancing operation,

wherein executing the balancing operation comprises;

performing a first move operation to move high priority data items of the multiple data items to the first hardware data storage device, and

performing a second move operation to evenly distribute the low priority data items among the identified hardware data storage devices,

wherein, in response to the balancing operation being executed, the first hardware data storage device has a greater amount of data than the second hardware data storage device, and

wherein, in response to the balancing operation being executed, the first hardware data storage device includes the high priority data items and at least one low priority data item of the low priority data items and the second hardware data storage device includes at least one low priority data item of the low priority data items.

10. The method of claim 9, further comprising:

determining if a first number of the multiple data items classified as low priority data items stored in the first hardware data storage device is greater than a second number of the multiple data items classified as low priority data items stored in the second hardware data storage device; and

in response to determining that the first number is greater than the second number, executing a second balancing operation that includes moving a portion of the low priority data items from the first hardware data storage device to the second hardware data storage device.

11. The method of claim 9, wherein, when the plurality of hardware data storage devices includes multiple hardware data storage devices of the first type, the first move operation evenly distributes the high priority data items among the multiple hardware data storage devices of the first type.

12. The method of claim 9, further comprising detecting a change in a number of the identified hardware data storage devices, wherein a second balancing operation is executed in response to detecting the change.

13. The method of claim 9, further comprising determining whether each data item classified as a high priority data item is stored in at least one identified hardware data storage device of the second type, wherein a second balancing operation is executed in response to determining that a particular data item classified as a high priority data item is stored in the at least one identified hardware data storage device of the second type.

14. A computer program product comprising a computer readable storage device storing computer readable program code embodied therewith, the computer readable program code comprising program code executable by a processor to:

assign, according to one or more priority assignment rules, priority tags to data items in a database system, the data items including data, the priority tag of each data item classifying the data item as a high priority data item or a low priority data item, wherein data items classified as high priority data items include frequently-accessed data or boot data;

determine whether each data item classified as a high priority data item is stored in a first hardware data storage device of a first type or in a second hardware data storage device of a second type, wherein the first hardware data storage device of the first type comprises a solid state memory and the second hardware data storage device comprises a hard disk memory, and wherein hardware data storage devices of the first type have faster memory access times than hardware data storage devices of the second type; and

in response to determining that a data item classified as a high priority data item is stored in the second hardware data storage device of the second type, execute a balancing operation that includes a first move operation and a second move operation,

wherein, in response to the balancing operation being executed, the first hardware data storage device has a greater amount of data than the second hardware data storage device,

wherein, in response to the balancing operation being executed, the first hardware data storage device includes the high priority data items and at least one low priority data item of the low priority data items and the second hardware data storage device includes at least one low priority data item of the low priority data items,

wherein the first move operation is performed to move the data item classified as the high priority data item from the second hardware data storage device of the second type to the first hardware data storage device of the first type, and

wherein the second move operation is performed to evenly distribute the low priority data items among the hardware data storage devices.

15. The computer program product of claim 14, wherein hardware data storage devices of the first type are rated as having higher energy efficiency than hardware data storage devices of the second type.

16. The computer program product of claim 14, wherein the program code is executable by the processor to:

determine that a particular hardware data storage device has been added for database use;

when the particular hardware data storage device has been added, identify the particular hardware data storage device as an identified hardware data storage device for storing data items in the database system; and

execute a second balancing operation in response to a determination that the particular hardware data storage device has been added.

17. A computing system for managing a database system, the computing system comprising:

at least one memory device for storing program code; and

at least one processor for executing the program code to;

assign priority tags according to one or more priority assignment rules to data items in the database system, the data items including data, the priority tag of each data item classifying the data item as a high priority data item or a low priority data item, wherein data items classified as high priority data items include frequently-accessed data or boot data;

determine whether each data item classified as a high priority data item is stored in at least one identified hardware data storage device of a first type or in at least one identified hardware data storage device of a second type, wherein hardware data storage devices of the first type are more energy efficient or faster than hardware data storage devices of the second type, wherein the at least one identified hardware data storage device of the first type comprises a solid state memory, and wherein the at least one identified hardware data storage device of a second type comprises a hard disk memory; and

in response to determining that a data item classified as a high priority data item is stored in the at least one identified hardware data storage device of the second type, execute a balancing operation that includes a first move operation and a second move operation,

wherein the first move operation is performed to move the data item classified as the high priority data item from the at least one identified hardware data storage device of the second type to the at least one identified hardware data storage device of the first type,

wherein the second move operation is performed to evenly distribute the low priority data items among the identified hardware data storage devices,

wherein, in response to the balancing operation being executed, the at least one identified hardware data storage device of the first type has a greater amount of data than the at least one identified hardware data storage device of the second type, and

wherein, in response to the balancing operation being executed, the at least one identified hardware data storage device of the first type includes the high priority data items and at least one low priority data item of the low priority data items and the at least one identified hardware data storage device of the second type includes at least one low priority data item of the low priority data items.

18. The computing system of claim 17, wherein the program code is executable by the at least one processor to:

determine that at least one hardware data storage device has been removed from database use; and

execute a second balancing operation in response to a determination that the at least one hardware data storage device is removed.

19. The computing system of claim 17, wherein, when there are more than one hardware data storage device of the first type in the database system, the first move operation evenly distributes data items classified as high priority data items among the hardware data storage devices of the first type.

20. The computing system of claim 17, wherein the hardware data storage devices of the first type are faster than the hardware data storage devices of the second type, and wherein the hardware data storage devices of the second type are less energy efficient than the hardware data storage devices of the first type.