Optimized caching of slices by a DS processing unit

Patent metadata

Field	Value
Publication number	US-10073658-B2
Application number	US-201615353157-A
Country	US
Kind code	B2
Filing date	Nov 16, 2016
Priority date	Nov 30, 2015
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A computing device includes an interface configured to interface and communicate with a dispersed storage network (DSN), a memory that stores operational instructions, and a processing module operably coupled to the interface and memory such that the processing module, when operable within the computing device based on the operational instructions, is configured to perform various operations. A computing device receives a data access request involving a set of EDSs associated with a data object that are distributedly stored among storage units (SUs) including first SU(s) coupled via a local network of the DSN and second SU(s) remotely located to the computing device and coupled via an external network of the DSN. The computing device caches within the at least one memory therein a subset of EDSs stored within the second SU(s) remotely located to the computing device and coupled to the computing device via the external network.

First claim

What is claimed is:

1. A computing device comprising:
an interface configured to interface and communicate with a dispersed storage network (DSN);
at least one memory that stores operational instructions and at least some encoded data slices (EDSs); and
a processing module operably coupled to the interface and to the at least one memory, wherein the processing module, when operable within the computing device based on the operational instructions, is configured to:
receive a data access request involving a set of EDSs associated with a data object that are distributedly stored among a plurality of storage units (SUs) that includes a first at least one SU that is coupled to the computing device via a local network of the DSN and a second at least one SU that is remotely located to the computing device and is coupled to the computing device via an external network of the DSN, wherein the data object is segmented into a 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 the set of EDSs, wherein a decode threshold number of EDSs are needed to recover the data segment, wherein a read threshold number of EDSs provides for reconstruction of the data segment, wherein a write threshold number 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;
cache within the at least one memory a subset of EDSs stored within the second at least one SU that is remotely located to the computing device and is coupled to the computing device via the external network; and
process the data access request involving the set of EDSs associated with the data object based on a first at least one EDS of the set of EDSs stored within the first at least one SU via the local network and based on at least one of a second at least one EDS of the set of EDSs stored within the at least one memory of the computing device or a third at least one EDS of the set of EDSs stored within the second at least one SU via the external network.

2. 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 process the data access request involving the set of EDSs associated with the data object including to:
retrieve firstly the second at least one EDS of the set of EDSs stored within the at least one memory of the computing device;
retrieve secondly the first at least one EDS of the set of EDSs stored within the first at least one SU via the local network; and
retrieve thirdly the third at least one EDS of the set of EDSs stored within the second at least one SU via the external network.

3. 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 process the data access request involving the set of EDSs associated with the data object including to:
retrieve at least one of the decode threshold number of EDSs, the read threshold number of EDSs, or the write threshold number of EDSs from the first at least one EDS of the set of EDSs stored within the first at least one SU via the local network and the second at least one EDS of the set of EDSs stored within the at least one memory of the computing device.

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:
determine a first revision level of a first EDS having a slice name of the set of EDSs stored within the first at least one SU with a second revision level of a second EDS having the slice name of the set of EDSs stored within the at least one memory of the computing device; and
when the first revision level compares unfavorably to the second revision level, request from the first at least one SU the first EDS having the slice name of the set of EDSs stored within the first at least one SU to replace the second EDS having the slice name of the set of EDSs stored within the at least one memory of the computing device.

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:
process the data access request involving the set of EDSs associated with the data object such that the set of EDSs associated with the data object are distributedly stored among the plurality of SUs that includes n SUs, wherein n is a positive integer greater than or equal to 2, such that a first approximately 1/n EDSs are stored within the first at least one SU and a second approximately 1/n EDSs are stored within the second at least one SU; and
cache within the at least one memory a sufficient number of EDSs stored within the second at least one SU that is remotely located to the computing device and is coupled to the computing device via the external network so that at least one of the decode threshold number of EDSs, the read threshold number of EDSs, or the write threshold number of EDSs may be retrieved from the at least one memory and the first at least one SU.

6. 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; and
the at least one memory includes a first memory that stores operational instructions and a second memory implemented that is separately from the first memory and that stores the at least some EDSs.

7. The computing device of claim 1 further comprising:
a SU of the plurality of SUs within the DSN, a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

8. 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).

9. A computing device comprising:
an interface configured to interface and communicate with a dispersed storage network (DSN);
at least one memory that stores operational instructions and at least some encoded data slices (EDSs); and
a processing module operably coupled to the interface and to the at least one memory, wherein the processing module, when operable within the computing device based on the operational instructions, is configured to:
receive a data access request involving a set of EDSs associated with a data object that are distributedly stored among a plurality of storage units (SUs) that includes n SUs, wherein n is a positive integer greater than or equal to 2, such that a first approximately 1/n EDSs are stored within a first at least one SU that is coupled to the computing device via a local network of the DSN and a second approximately 1/n EDSs are stored within a second at least one SU that is remotely located to the computing device and is coupled to the computing device via an external network of the DSN, wherein the data object is segmented into a 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 the set of EDSs, wherein a decode threshold number of EDSs are needed to recover the data segment, wherein a read threshold number of EDSs provides for reconstruction of the data segment, wherein a write threshold number of EDSs provides for a successful transfer of the set of EDSs from a first at least one location in the DSN to

Assignees

• IBM

Inventors

• Motwani Manish
• Wozniak Ethan S

Classifications

• G06F2211/1007

  Addressing errors, i.e. silent errors in RAID, e.g. sector slipping and addressing errors · CPC title

• G06F12/0891

  using clearing, invalidating or resetting means · CPC title

• G06F3/0644

  Management of space entities, e.g. partitions, extents, pools · CPC title

• G06F2212/403

  Error protection encoding, e.g. using parity or ECC codes · CPC title

• H04L67/1097

  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 title