TIERED CACHING AND MIGRATION IN DIFFERING GRANULARITIES

• US 20140208018A1
• Filed: 01/22/2013
• Published: 07/24/2014
• Est. Priority Date: 01/22/2013
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: BENHASE, Michael T., GUPTA, Lokesh M., SONG, Cheng-Chung
• Granted Patent: US 9,037,791 B2
• Time in Patent Office: Days
• US Class Current: 711/113
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 12/0806 Multiuser, multiprocessor or multiprocessing cache systems
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 12/0897 with two or more cache hierarchy levels with multilevel cache hierarchies G06F12/0811
• CPC Class Codes: G06F 2212/1024 Latency reduction
• CPC Class Codes: G06F 2212/205 Hybrid memory, e.g. using both volatile and non-volatile memory
• CPC Class Codes: G06F 2212/217 Hybrid disk, e.g. using both magnetic and solid state storage devices
• CPC Class Codes: G06F 2212/254 Distributed memory
• CPC Class Codes: G06F 2212/261 Storage comprising a plurality of storage devices
• CPC Class Codes: G06F 2212/284 being distributed
• CPC Class Codes: G06F 2212/608 Details relating to cache mapping
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0649 Lifecycle management
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0682 Tape device
• CPC Class Codes: G06F 3/0685 : Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays

Abstract

For data processing in a computing storage environment by a processor device, the computing storage environment incorporating at least high-speed and lower-speed caches, and managed tiered levels of storage, groups of data segments are migrated between the tiered levels of storage such that uniformly hot ones of the groups of data segments are migrated to use a Solid State Drive (SSD) portion of the tiered levels of storage, clumped hot ones of the groups of data segments are migrated to use the SSD portion while using the lower-speed cache for a remaining portion of the clumped hot ones, and sparsely hot ones of the groups of data segments are migrated to use the lower-speed cache while using a lower one of the tiered levels of storage for a remaining portion of the sparsely hot ones.

Claims

1. A method for data processing in a computing storage environment by a processor device, the computing storage environment incorporating at least high-speed and lower-speed caches, and tiered levels of storage, the method comprising:

migrating groups of data segments between the tiered levels of storage such that uniformly hot ones of the groups of data segments are migrated to use a Solid State Drive (SSD) portion of the tiered levels of storage, clumped hot ones of the groups of data segments are migrated to use the SSD portion while using the lower-speed cache for a remaining portion of the clumped hot ones, and sparsely hot ones of the groups of data segments are migrated to use the lower-speed cache while using a lower one of the tiered levels of storage for a remaining portion of the sparsely hot ones.

2. The method of claim 1, further including determining the uniformly hot groups of data segments using a first heat map for a selected one of the group of the data segments, the heat map having a first, largest granularity.

3. The method of claim 2, further including determining the uniformly hot groups of data segments by determining that first heat map is hotter than a first predetermined threshold.

4. The method of claim 3, wherein determining that the first heat map is hotter than the first predetermined threshold further includes determining that at least a predetermined number of granular portions of the selected one of the group of data segments is hotter than the first predetermined threshold.

5. The method of claim 2, further including determining the clumped hot groups of data segments using a second heat map having a granularity smaller than the first, largest granularity of the first heat map.

6. The method of claim 5, further including determining the clumped hot groups of data segments by determining that the first heat map is not hotter than the predetermined threshold, yet at least a portion of the second heat map is hotter than a second predetermined threshold.

7. The method of claim 5, further including determining the sparsely hot groups of data segments by determining that neither the first heat map nor the second heat map are hotter than the first and second predetermined thresholds, respectively.

8. The method of claim 1, further including migrating a selected one of the groups of data segments between the SSD portion and the lower-speed cache by:

if the selected group is cached in the lower-speed cache and is determined to become one of uniformly hot and clumped hot, migrating the selected group from the lower-speed cache to the SSD portion while refraining from processing data retained in the lower-speed cache until the selected group is fully migrated to the SSD portion.

9. The method of claim 1, further including migrating a selected one of the groups of data segments between the SSD portion and the lower-speed cache by:

if the selected group is cached in the SSD portion and is determined to become sparesly hot, migrating the selected group from the SSD portion to the lower-speed cache, and subsequently, migrating the selected group from the SSD portion to a Hard Disk Device (HDD).

10. A system for data processing in a computing storage environment, the computing storage environment incorporating at least high-speed and lower-speed caches, and tiered levels of storage, comprising:

a processor device, operable in the computing storage environment, wherein the processor device;

migrates groups of data segments between the tiered levels of storage such that uniformly hot ones of the groups of data segments are migrated to use a Solid State Drive (SSD) portion of the tiered levels of storage, clumped hot ones of the groups of data segments are migrated to use the SSD portion while using the lower-speed cache for a remaining portion of the clumped hot ones, and sparsely hot ones of the groups of data segments are migrated to use the lower-speed cache while using a lower one of the tiered levels of storage for a remaining portion of the sparsely hot ones.

11. The system of claim 10, wherein the processor device determines the uniformly hot groups of data segments using a first heat map for a selected one of the group of the data segments, the heat map having a first, largest granularity.

12. The system of claim 11, wherein the processor device determines the uniformly hot groups of data segments by determining that first heat map is hotter than a first predetermined threshold.

13. The system of claim 12, wherein the processor device, pursuant to determining that the first heat map is hotter than the first predetermined threshold, determines that at least a predetermined number of granular portions of the selected one of the group of data segments is hotter than the first predetermined threshold.

14. The system of claim 11, wherein the processor device determines the clumped hot groups of data segments using a second heat map having a granularity smaller than the first, largest granularity of the first heat map.

15. The system of claim 14, wherein the processor device, pursuant to determining the clumped hot groups of data segments, determines that the first heat map is not hotter than the predetermined threshold, yet at least a portion of the second heat map is hotter than a second predetermined threshold.

16. The system of claim 14, wherein the processor device determines the sparsely hot groups of data segments by determining that neither the first heat map nor the second heat map are hotter than the first and second predetermined thresholds, respectively.

17. The system of claim 10, wherein the processor device migrates a selected one of the groups of data segments between the SSD portion and the lower-speed cache by:

if the selected group is cached in the lower-speed cache and is determined to become one of uniformly hot and clumped hot, migrating the selected group from the lower-speed cache to the SSD portion while refraining from processing data retained in the lower-speed cache until the selected group is fully migrated to the SSD portion.

18. The system of claim 10, wherein the processor device migrates a selected one of the groups of data segments between the SSD portion and the lower-speed cache by:

if the selected group is cached in the SSD portion and is determined to become sparsely hot, migrating the selected group from the SSD portion to the lower-speed cache, and subsequently, migrating the selected group from the SSD portion to a Hard Disk Device (HDD).

19. A computer program product for data processing in a computing storage environment by a processor device, the computing storage environment incorporating at least high-speed and lower-speed caches, and tiered levels of storage, the computer program product comprising a non-transitory computer-readable storage medium having computer-readable program code portions stored therein, the computer-readable program code portions comprising:

a first executable portion that migrates groups of data segments between the tiered levels of storage such that uniformly hot ones of the groups of data segments are migrated to use a Solid State Drive (SSD) portion of the tiered levels of storage, clumped hot ones of the groups of data segments are migrated to use the SSD portion while using the lower-speed cache for a remaining portion of the clumped hot ones, and sparsely hot ones of the groups of data segments are migrated to use the lower-speed cache while using a lower one of the tiered levels of storage for a remaining portion of the sparsely hot ones.

20. The computer program product of claim 19, further including a second executable portion that determines the uniformly hot groups of data segments using a first heat map for a selected one of the group of the data segments, the heat map having a first, largest granularity.

21. The computer program product of claim 20, further including a third executable portion that determines the uniformly hot groups of data segments by determining that first heat map is hotter than a first predetermined threshold.

22. The computer program product of claim 21, further including a fourth executable portion that, pursuant to determining that the first heat map is hotter than the first predetermined threshold, determines that at least a predetermined number of granular portions of the selected one of the group of data segments is hotter than the first predetermined threshold.

23. The computer program product of claim 20, further including a third executable portion that determines the clumped hot groups of data segments using a second heat map having a granularity smaller than the first, largest granularity of the first heat map.

24. The computer program product of claim 23, further including a fourth executable portion that, pursuant to determining the clumped hot groups of data segments, determines that the first heat map is not hotter than the predetermined threshold, yet at least a portion of the second heat map is hotter than a second predetermined threshold.

25. The computer program product of claim 23, further including a fourth executable portion that determines the sparsely hot groups of data segments by determining that neither the first heat map nor the second heat map are hotter than the first and second predetermined thresholds, respectively.

26. The computer program product of claim 19, further including a second executable portion that migrates a selected one of the groups of data segments between the SSD portion and the lower-speed cache by:

if the selected group is cached in the lower-speed cache and is determined to become one of uniformly hot and clumped hot, migrating the selected group from the lower-speed cache to the SSD portion while refraining from processing data retained in the lower-speed cache until the selected group is fully migrated to the SSD portion.

27. The computer program product of claim 19, further including a second executable portion that migrates a selected one of the groups of data segments between the SSD portion and the lower-speed cache by:

if the selected group is cached in the SSD portion and is determined to become sparsely hot, migrating the selected group from the SSD portion to the lower-speed cache, and subsequently, migrating the selected group from the SSD portion to a Hard Disk Device (HDD).