Utilizing reallocation via a decentralized or distributed, agreement protocol (DAP) for storage unit (SU) replacement

• US 10,142,176 B2
• Filed: 03/27/2018
• Issued: 11/27/2018
• Est. Priority Date: 07/18/2016
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Baptist, Andrew D., Motwani, Manish, Resch, Jason K.
• Primary Examiner(s): Keehn, Richard G
• Application Number:
  US15/936,608
• Publication Number:
  US 20180219731A1
• Time in Patent Office: 245 Days
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 41/0813 characterised by the conditions triggering a change of settings
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/146 Markers for unambiguous identification of a particular session, e.g. session cookie or URL-encoding
• CPC Class Codes: H04L 67/148 Migration or transfer of sessions

Abstract

Based on a system configuration change (e.g., of a Decentralized, or Distributed, Agreement Protocol (DAP)) within a dispersed storage network (DSN) (e.g., from a first to a second system configuration of the DAP), a computing device directs a storage unit to be replaced (SUTBR) to transfer encoded data slices (EDSs) stored therein to a replacement storage unit (RSU). During transfer of the EDSs (e.g., from SUTBR to RSU), the computing device directs the SUTBR to service read and/or write requests for EDS(s) stored therein to operate based on a first system configuration of the DAP. When the EDSs have been successfully transferred from the SUTBR to the RSU, the computing device directs the RSU to service read and/or write requests for the EDS(s) stored therein to operate based on a second system configuration of the DAP.

Claims

1. A storage unit (SU) comprising:

an interface configured to interface and communicate with a dispersed or distributed storage network (DSN);

memory that stores operational instructions; and

processing circuitry operably coupled to the interface and to the memory, wherein the processing circuitry is configured to execute the operational instructions to;

based on a change from a first system configuration of a Decentralized, or Distributed, Agreement Protocol (DAP) to a second system configuration of the DAP based on a storage unit to be replaced (SUTBR) within a plurality of storage units (SUs) that includes the SU within the DSN, operate based on the first system configuration of the DAP and service read and write requests from one or more computing devices for at least one encoded data slice (EDS) that is stored within the SU based on the first system configuration of the DAP during transfer of a plurality of EDSs from the SUTBR to a replacement storage unit (RSU) for storage within the RSU, wherein;

the first system configuration of the DAP and the second system configuration of the DAP respectively provide for deterministic calculation of locations of EDS sets that correspond respectively to a plurality of data segments of a data object that are distributedly stored across the plurality of SUs within the DSN;

the data object is segmented into the plurality of data segments, and a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce a set of EDSs of the EDS sets that is of pillar width having a plurality of EDS names;

a write threshold number of EDSs of the set of EDSs provides for a successful transfer of the set of EDSs from a first at least one location in the DSN to a second at least one location in the DSN; and

operate based on the second system configuration of the DAP and service other read and write requests from the one or more computing devices for the at least one EDS that is stored within the SU based on the second system configuration of the DAP after the plurality of EDSs have been successfully transferred from the SUTBR to the RSU.

2. The SU of claim 1, wherein:

a read threshold number of EDSs of the set of EDSs provides for reconstruction of the data segment;

the data object is associated with a unique source name; and

each EDS name of the plurality of EDS names includes a reference to the unique source name.

3. The SU of claim 2, wherein:

the DAP, when executed using the unique source name and coefficients regarding the plurality of SUs of the DSN, produces a ranking of the plurality of SUs that deterministically identifies those SUs of the plurality of SUs that store the EDS sets including the set of EDSs of the EDS sets; and

processing circuitry is further configured to execute the operational instructions to update at least one of the coefficients that corresponds to the SU based on the change from the first system configuration of the DAP to the second system configuration of the DAP.

4. The SU of claim 1, wherein:

a storage resource map (SRM) for the plurality of SUs including the SUTBR is updated by replacing a first entry associated with the SUTBR with a second entry associated with the RSU after the plurality of EDSs have been successfully transferred from the SUTBR to the RSU.

5. The SU of claim 1, wherein the processing circuitry is further configured to execute the operational instructions to:

receive direction from at least one of the one or more computing devices to operate based on the first system configuration of the DAP and operate based on the second system configuration of the DAP.

6. The SU of claim 1, wherein the SU is located at a first premises that is remotely located from at least one of the one or more computing devices within the DSN.

7. The SU of claim 1, wherein at least one of the one or more computing devices includes a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

8. The SU of claim 1, wherein the DSN includes at least one of a wireless communication system, a wire lined communication system, a non-public intranet system, a public internet system, a local area network (LAN), or a wide area network (WAN).

9. A storage unit (SU) comprising:

an interface configured to interface and communicate with a dispersed or distributed storage network (DSN);

memory that stores operational instructions; and

processing circuitry operably coupled to the interface and to the memory, wherein the processing circuitry is configured to execute the operational instructions to;

based on a change from a first system configuration of a Decentralized, or Distributed, Agreement Protocol (DAP) to a second system configuration of the DAP based on a storage unit to be replaced (SUTBR) within a plurality of storage units (SUs) that includes the SU within the DSN, operate based on the first system configuration of the DAP and service read and write requests from one or more computing devices for at least one encoded data slice (EDS) that is stored within the SU based on the first system configuration of the DAP during transfer of a plurality of EDSs from the SUTBR to a replacement storage unit (RSU) for storage within the RSU, wherein;

the first system configuration of the DAP and the second system configuration of the DAP respectively provide for deterministic calculation of locations of EDS sets that correspond respectively to a plurality of data segments of a data object that are distributedly stored across the plurality of SUs within the DSN;

the data object is segmented into the plurality of data segments, and a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce a set of EDSs of the EDS sets that is of pillar width having a plurality of EDS names;

a read threshold number of EDSs of the set of EDSs provides for reconstruction of the data segment, and a write threshold number of EDSs of the set of EDSs provides for a successful transfer of the set of EDSs from a first at least one location in the DSN to a second at least one location in the DSN;

the data object is associated with a unique source name; and

each EDS name of the plurality of EDS names includes a reference to the unique source name; and

operate based on the second system configuration of the DAP and service other read and write requests from the one or more computing devices for the at least one EDS that is stored within the SU based on the second system configuration of the DAP after the plurality of EDSs have been successfully transferred from the SUTBR to the RSU, wherein a storage resource map (SRM) for the plurality of SUs including the SUTBR is updated by replacing a first entry associated with the SUTBR with a second entry associated with the RSU after the plurality of EDSs have been successfully transferred from the SUTBR to the RSU.

10. The SU of claim 9, wherein:

the DAP, when executed using the unique source name and coefficients regarding the plurality of SUs of the DSN, produces a ranking of the plurality of SUs that deterministically identifies those SUs of the plurality of SUs that store the EDS sets including the set of EDSs of the EDS sets; and

processing circuitry is further configured to execute the operational instructions to update at least one of the coefficients that corresponds to the SU based on the change from the first system configuration of the DAP to the second system configuration of the DAP.

11. The SU of claim 9, wherein the processing circuitry is further configured to execute the operational instructions to:

receive direction from at least one of the one or more computing devices to operate based on the first system configuration of the DAP and operate based on the second system configuration of the DAP.

12. The SU of claim 9, wherein at least one of:

the SU is located at a first premises that is remotely located from at least one of the one or more computing devices within the DSN;

or

the at least one of the one or more computing devices includes a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

13. The SU of claim 9, wherein the DSN includes at least one of a wireless communication system, a wire lined communication system, a non-public intranet system, a public internet system, a local area network (LAN), or a wide area network (WAN).

14. A method for execution by a storage unit (SU), the method comprising:

based on a change from a first system configuration of a Decentralized, or Distributed, Agreement Protocol (DAP) to a second system configuration of the DAP based on a storage unit to be replaced (SUTBR) within a plurality of storage units (SUs) that includes the SU within a dispersed or distributed storage network (DSN), operating based on the first system configuration of the DAP and servicing, via an interface of the SU that is configured to interface and communicate with the DSN, read and write requests from one or more computing devices for at least one encoded data slice (EDS) that is stored within the SU based on the first system configuration of the DAP during transfer of a plurality of EDSs from the SUTBR to a replacement storage unit (RSU) for storage within the RSU, wherein;

the first system configuration of the DAP and the second system configuration of the DAP respectively provide for deterministic calculation of locations of EDS sets that correspond respectively to a plurality of data segments of a data object that are distributedly stored across the plurality of SUs within the DSN;

the data object is segmented into the plurality of data segments, and a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce a set of EDSs of the EDS sets that is of pillar width having a plurality of EDS names;

a write threshold number of EDSs of the set of EDSs provides for a successful transfer of the set of EDSs from a first at least one location in the DSN to a second at least one location in the DSN; and

operating based on the second system configuration of the DAP and servicing, via the interface, other read and write requests from the one or more computing devices for the at least one EDS that is stored within the SU based on the second system configuration of the DAP after the plurality of EDSs have been successfully transferred from the SUTBR to the RSU.

15. The method of claim 14, wherein:

a read threshold number of EDSs of the set of EDSs provides for reconstruction of the data segment;

the data object is associated with a unique source name; and

each EDS name of the plurality of EDS names includes a reference to the unique source name.

16. The method of claim 15, wherein:

the DAP, when executed using the unique source name and coefficients regarding the plurality of SUs of the DSN, produces a ranking of the plurality of SUs that deterministically identifies those SUs of the plurality of SUs that store the EDS sets including the set of EDSs of the EDS sets; and

further comprising;

updating at least one of the coefficients that corresponds to the SU based on the change from the first system configuration of the DAP to the second system configuration of the DAP.

17. The method of claim 14, wherein:

a storage resource map (SRM) for the plurality of SUs including the SUTBR is updated by replacing a first entry associated with the SUTBR with a second entry associated with the RSU after the plurality of EDSs have been successfully transferred from the SUTBR to the RSU.

18. The method of claim 14, wherein:

a storage resource map (SRM) for the plurality of SUs including the SUTBR is updated by replacing a first entry associated with the SUTBR with a second entry associated with the RSU after the plurality of EDSs have been successfully transferred from the SUTBR to the RSU.

19. The method of claim 14 further comprising:

receiving, via the interface, direction from at least one of the one or more computing devices to operate based on the first system configuration of the DAP and operate based on the second system configuration of the DAP.

20. The method of claim 14, wherein at least one of:

the SU is located at a first premises that is remotely located from at least one of the one or more computing devices within the DSN;

the at least one of the one or more computing devices includes a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device;

or

the DSN includes at least one of a wireless communication system, a wire lined communication system, a non-public intranet system, a public internet system, a local area network (LAN), or a wide area network (WAN).