Focused storage pool expansion to prevent a performance degradation

• US 10,360,103 B2
• Filed: 07/18/2016
• Issued: 07/23/2019
• Est. Priority Date: 07/18/2016
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Leggette, Wesley B.
• Primary Examiner(s): Blair, April Y
• Assistant Examiner(s): Gandhi, Dipakkumar B
• Application Number:
  US15/212,666
• Publication Number:
  US 20180018230A1
• Time in Patent Office: 1,100 Days
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems

Abstract

Based on a system configuration change (e.g., of a Decentralized, or Distributed, Agreement Protocol (DAP)) within a dispersed storage network (DSN), a computing device identifies a reallocating encoded data slice (EDS) number that is no more than a pillar width minus a performance threshold. The computing device then directs storage units (SUs) to update system configuration of the DAP (e.g., from a first to a second system configuration) by throttling and controlling the number of SUs permitted to update at a time. For example, the computing device permits no more than the reallocating EDS number of SUs to perform simultaneous (or substantially or approximately simultaneous) update of the system configuration of the DAP. The computing device also directs the SUs to operate based on the first system configuration before the condition(s) is/are met and then to operate based on the second system configuration after the condition (s) is/are met.

Claims

1. A computing device comprising:

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

memory that stores operational instructions; and

a processing module operably coupled to the interface and to the memory, wherein the processing module, when operable within the computing device based on the operational instructions, is configured to;

detect, via the interface and via the DSN, 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 addition or removal of at least one storage unit (SU) within a plurality of storage units (SUs) within the DSN, wherein the first system configuration of the DAP and the second system configuration of the DAP respectively provide for deterministic calculation of locations of encoded data slice (EDS) sets that correspond respectively to a plurality of data segments of a data object that are distributedly stored across the plurality of storage units SUs within the DSN, wherein the data object is segmented into the plurality of data segments, wherein 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, wherein a read threshold number of EDSs of the set of EDSs provides for reconstruction of the data segment, wherein 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;

identify a reallocating EDS number that is no more than the pillar width minus a performance threshold;

direct, via the interface and via the DSN, the plurality of SUs to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than the reallocating EDS number of SUs of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP;

direct, via the interface and via the DSN, the plurality of SUs to operate based on the first system configuration of the DAP when fewer than a number of SUs of the plurality of SUs corresponding to at least one of the read threshold number of EDSs of the set of EDSs or the write threshold number of EDSs of the set of EDSs have successfully updated from the first system configuration of the DAP to the second system configuration of the DAP; and

direct, via the interface and via the DSN, the plurality of SUs to operate based on the second system configuration of the DAP after the number of SUs of the plurality of SUs corresponding to the at least one of the read threshold number of EDSs of the set of EDSs or the write threshold number of EDSs of the set of EDSs have successfully updated from the first system configuration of the DAP to the second system configuration of the DAP.

2. The computing device of claim 1, wherein the performance threshold includes:

the pillar width minus the read threshold number of EDSs of the set of EDSs;

or

the pillar width minus the write threshold number of EDSs of the set of EDSs.

3. The computing device of claim 1, wherein the performance threshold includes:

the pillar width minus the read threshold number of EDSs of the set of EDSs plus a first number;

or

the pillar width minus the write threshold number of EDSs of the set of EDSs plus a second number.

4. The computing device of claim 1, wherein the processing module, when operable within the computing device based on the operational instructions, is further configured to:

direct a first subset of the plurality of SUs to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than the reallocating EDS number of SUs within the first subset of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP; and

direct a second subset of the plurality of SUs to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than another reallocating EDS number of SUs within the second subset of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP.

5. The computing device of claim 1, wherein the processing module, when operable within the computing device based on the operational instructions, is further configured to:

identify another reallocating EDS number that is no more than the pillar width minus another performance threshold during or after update of at least one SU of the plurality of SUs from the first system configuration of the DAP to the second system configuration of the DAP; and

direct remaining SUs of the plurality of SUs, which exclude at least one SU of the plurality of SUs, to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than the another reallocating EDS number of SUs of the remaining SUs of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP.

6. The computing device of claim 1, wherein the processing module, when operable within the computing device based on the operational instructions, is further configured to:

identify the reallocating EDS number that is no more than the pillar width minus the performance threshold based on at least one of a first operational parameter that characterizes a SU of the plurality of SUs, identify a second operational parameter that characterizes a communication pathway within the DSN, update status of the plurality of SUs updating from the first system configuration of the DAP to the second system configuration of the DAP, or update status of at least one SU updating from the first system configuration of the DAP to the second system configuration of the DAP.

7. The computing device of claim 1, wherein the computing device is located at a first premises that is remotely located from at least one SU of the plurality of SUs within the DSN.

8. The computing device of claim 1 further comprising:

a SU of the plurality of SUs within the DSN.

9. The computing device of claim 1 further comprising:

a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

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

11. A method for execution by a computing device, the method comprising:

detecting, via an interface of the computing device that is configured to interface and communicate with a dispersed storage network (DSN), 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 addition or removal of at least one storage unit (SU) within a plurality of storage units (SUs) within the DSN, wherein the first system configuration of the DAP and the second system configuration of the DAP respectively provide for deterministic calculation of locations of encoded data slice (EDS) sets that correspond respectively to a plurality of data segments of a data object that are distributedly stored across the plurality of storage units SUs within the DSN, wherein the data object is segmented into the plurality of data segments, wherein 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, wherein a read threshold number of EDSs of the set of EDSs provides for reconstruction of the data segment, wherein 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;

identifying a reallocating EDS number that is no more than the pillar width minus a performance threshold;

directing, via the interface of the computing device and via the DSN, the plurality of SUs to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than the reallocating EDS number of SUs of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP;

directing, via the interface of the computing device and via the DSN, the plurality of SUs to operate based on the first system configuration of the DAP when fewer than a number of SUs of the plurality of SUs corresponding to at least one of the read threshold number of EDSs of the set of EDSs or the write threshold number of EDSs of the set of EDSs have successfully updated from the first system configuration of the DAP to the second system configuration of the DAP; and

directing, via the interface of the computing device and via the DSN, the plurality of SUs to operate based on the second system configuration of the DAP after the number of SUs of the plurality of SUs corresponding to the at least one of the read threshold number of EDSs of the set of EDSs or the write threshold number of EDSs of the set of EDSs have successfully updated from the first system configuration of the DAP to the second system configuration of the DAP.

12. The method of claim 11, wherein the performance threshold includes:

the pillar width minus the read threshold number of EDSs of the set of EDSs;

or

the pillar width minus the write threshold number of EDSs of the set of EDSs.

13. The method of claim 11, wherein the performance threshold includes:

the pillar width minus the read threshold number of EDSs of the set of EDSs plus a first number;

or

the pillar width minus the write threshold number of EDSs of the set of EDSs plus a second number.

14. The method of claim 11 further comprising:

directing a first subset of the plurality of SUs to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than the reallocating EDS number of SUs within the first subset of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP; and

directing a second subset of the plurality of SUs to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than another reallocating EDS number of SUs within the second subset of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP.

15. The method of claim 11 further comprising:

identifying another reallocating EDS number that is no more than the pillar width minus another performance threshold during or after update of at least one SU of the plurality of SUs from the first system configuration of the DAP to the second system configuration of the DAP; and

directing remaining SUs of the plurality of SUs, which exclude at least one SU of the plurality of SUs, to update from the first system configuration of the DAP to the second system configuration of the DAP including permitting no more than the another reallocating EDS number of SUs of the remaining SUs of the plurality of SUs to perform simultaneous update from the first system configuration of the DAP to the second system configuration of the DAP.

16. The method of claim 11 further comprising:

identifying the reallocating EDS number that is no more than the pillar width minus the performance threshold based on at least one of a first operational parameter that characterizes a SU of the plurality of SUs, identifying a second operational parameter that characterizes a communication pathway within the DSN, updating status of the plurality of SUs updating from the first system configuration of the DAP to the second system configuration of the DAP, or updating status of at least one SU updating from the first system configuration of the DAP to the second system configuration of the DAP.

17. The method of claim 11, wherein the computing device is located at a first premises that is remotely located from at least one SU of the plurality of SUs within the DSN.

18. The method of claim 11, wherein the computing device includes a SU of the plurality of SUs within the DSN.

19. The method of claim 11, wherein the computing device includes a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

20. The method of claim 11, wherein the DSN includes at least one of a wireless communication system, a wire lined communication systems, a non-public intranet system, a public internet system, a local area network (LAN), or a wide area network (WAN).