Policy based slice deletion in a dispersed storage network

• US 9,866,595 B2
• Filed: 07/27/2016
• Issued: 01/09/2018
• Est. Priority Date: 12/29/2009
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Grube, Gary W., Resch, Jason K.
• Primary Examiner(s): HERZOG, MADHURI R
• Application Number:
  US15/220,944
• Publication Number:
  US 20160359918A1
• Time in Patent Office: 531 Days
• CPC Class Codes: G06F 11/00 Error detection; Error correction; Monitoring error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00
• CPC Class Codes: G06F 11/08 Error detection or correction by redundancy in data representation, e.g. by using checking codes
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1096 Parity calculation or recalculation after configuration or reconfiguration of the system
• CPC Class Codes: G06F 16/125 characterised by the use of retention policies retention policies for HSM systems G06F16/185
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 2221/2137 Time limited access, e.g. to a computer or data
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: H04L 2012/6467 Information loss recovery, e.g. error correction, prediction
• CPC Class Codes: H04L 2463/121 Timestamp cryptographic mechanisms or cryptographic arrangements involving time stamps H04L9/3297
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 63/108 when the policy decisions are valid for a limited amount of time
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227
• 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]

Abstract

A method for execution in a dispersed storage network operates to determine one or more slice names of one or more slices to consider for deletion; determine an access policy corresponding to the one or more slices; determine a current timestamp; and determine when there is no future slice availability for the one or more slices, based on the current timestamp and the access policy. When there is no future slice availability for the one or more slices, the dispersed storage network determines when reconsideration is available and sends a reconsideration message to a reconsideration entity when the reconsideration is determined to be available. The dispersed storage network deletes the one or more slices when the reconsideration is determined to be unavailable.

Claims

1. A method for execution by a processing system of a dispersed storage network that includes a processor, the method comprises:

determining one or more slice names of one or more slices to consider for deletion;

determining an access policy corresponding to the one or more slices that includes a time varying accessibility pattern;

determining a current timestamp;

determining whether there is no future slice availability for the one or more slices, based on the current timestamp and the access policy;

when there is no future slice availability for the one or more slices;

determining whether reconsideration regarding deletion of the one or more slices is available based on the access policy;

deleting the one or more slices when the reconsideration is determined to be unavailable;

when the reconsideration is determined to be available;

sending a reconsideration request message to a reconsideration entity;

receiving a reconsideration response message in response; and

deleting the one or more slices when the reconsideration response message indicates that the reconsideration is denied.

2. The method of claim 1, wherein the one or more slice names include one of:

a plurality of discrete and non-contiguous slice names, a contiguous range of slice names associated with a common data segment or a contiguous range of slice names associated with a common data object.

3. The method of claim 1, wherein determining one or more slice names is based on one or more of:

where a previous deletion process ended, a starting DSN address, a lookup, a command, a request, a random number, a vault ID, a data object ID, and a local virtual DSN address to a physical location table.

4. The method of claim 1, wherein determining the access policy includes retrieving the access policy based on the one or more slice names.

5. The method of claim 1, wherein determining when the reconsideration is available is further based on one or more of:

a reconsideration time window, a user device ID, a vault lookup, a command, a predetermination, a DS managing unit message, and the current timestamp.

6. The method of claim 1, wherein the reconsideration entity is at least one of:

a user device, a DST processing unit, a storage integrity processing unit, a managing unit, or a DST execution unit.

7. The method of claim 1, wherein the time varying accessibility pattern includes a plurality of time frames, and wherein a read threshold of pillars of a vault are only available across at least two time frames.

8. The method of claim 1, further comprising:

maintaining storage of the one or more slices when the reconsideration response message includes a new access policy corresponding to the one or more slices; and

storing the new access policy.

9. A processing system of a dispersed storage network comprises:

at least one processor;

a memory that stores operational instructions, that when executed by the at least one processor cause the processing system to;

determine one or more slice names of one or more slices to consider for deletion;

determine an access policy corresponding to the one or more slices that includes a time varying accessibility pattern;

determine a current timestamp;

determine whether there is no future slice availability for the one or more slices, based on the current timestamp and the access policy;

when there is no future slice availability for the one or more slices;

determine whether reconsideration regarding deletion of the one or more slices is available based on the access policy;

delete the one or more slices when the reconsideration is determined to be unavailable;

when the reconsideration is determined to be available;

send a reconsideration request message to a reconsideration entity;

receive a reconsideration response message in response; and

delete the one or more slices when the reconsideration response message indicates that the reconsideration is denied.

10. The processing system of claim 9, wherein the one or more slice names include one of:

a plurality of discrete and non-contiguous slice names, a contiguous range of slice names associated with a common data segment or a contiguous range of slice names associated with a common data object.

11. The processing system of claim 9, wherein determining one or more slice names is based on one or more of:

where a previous deletion process ended, a starting DSN address, a lookup, a command, a request, a random number, a vault ID, a data object ID, and a local virtual DSN address to a physical location table.

12. The processing system of claim 9, wherein determining the access policy includes retrieving the access policy based on the one or more slice names.

13. The processing system of claim 9, wherein determining when the reconsideration is available is further based on one or more of:

a reconsideration time window, a user device ID, a vault lookup, a command, a predetermination, a DS managing unit message, and the current timestamp.

14. The processing system of claim 9, wherein the reconsideration entity is at least one of:

a user device, a DST processing unit, a storage integrity processing unit, a managing unit, or a DST execution unit.

15. The processing system of claim 9, wherein the time varying accessibility pattern includes a plurality of time frames, and wherein a read threshold of pillars of a vault are only available across at least two time frames.

16. The processing system of claim 9, wherein the operational instructions, when executed by the at least one processor further cause the processing system to:

maintain storage of the one or more slices when the reconsideration response message includes a new access policy corresponding to the one or more slices; and

store the new access policy.

17. A non-transitory computer readable storage medium comprises:

at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage network (DSN) that includes a processor and a memory, causes the processing system to;

determine one or more slice names of one or more slices to consider for deletion;

determine an access policy corresponding to the one or more slices that includes a time varying accessibility pattern;

determine a current timestamp;

determine whether there is no future slice availability for the one or more slices, based on the current timestamp and the access policy;

when there is no future slice availability for the one or more slices;

determine whether reconsideration regarding deletion of the one or more slices is available based on the access policy;

delete the one or more slices when the reconsideration is determined to be unavailable;

when the reconsideration is determined to be available;

send a reconsideration request message to a reconsideration entity

receive a reconsideration response message in response; and

delete the one or more slices when the reconsideration response message indicates that the reconsideration is denied.

18. The non-transitory computer readable storage medium of claim 17, wherein determining when the reconsideration is available is further based on one or more of:

a reconsideration time window, a user device ID, a vault lookup, a command, a predetermination, a DS managing unit message, and the current timestamp.

19. The non-transitory computer readable storage medium of claim 17, wherein the time varying accessibility pattern includes a plurality of time frames, and wherein a read threshold of pillars of a vault are only available across at least two time frames.

20. The non-transitory computer readable storage medium of claim 17, wherein the operational instructions, when executed by the processor further cause the processing system to:

maintain storage of the one or more slices when the reconsideration response message includes a new access policy corresponding to the one or more slices; and

store the new access policy.