Collection synchronization using equality matched network names

• US 10,075,521 B2
• Filed: 04/07/2014
• Issued: 09/11/2018
• Est. Priority Date: 04/07/2014
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Mosko, Marc E.
• Primary Examiner(s): Srivastava, Vivek
• Assistant Examiner(s): Doan, Hien
• Application Number:
  US14/247,169
• Publication Number:
  US 20150288755A1
• Time in Patent Office: 1,618 Days
• Field of Search: None
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

One embodiment provides a system that facilitates synchronization collections of data between a local and a remote node by using exact match names. During operation, a local node receives an advertisement corresponding to a remote manifest at a remote node. A manifest represents a collection of content objects at a node. In some embodiments, a manifest corresponds to a root hash value that identifies the content objects of the collection. The local node determines that the local manifest and the remote manifest both indicate the same collection of content objects. The local node then determines if the content of the collections are different by comparing the root hash value of the local manifest with the root hash value of the remote manifest. Responsive to determining that the root hash values of the manifests are different, the local node retrieves the remote manifest by sending a request for the remote manifest. The local node determines which content objects identified in the remote manifest are different from the content objects identified in the local manifest. The local node transmits a set of interests for the content objects that are different and receives the requested set of content objects, thereby facilitating synchronization of content objects associated with the manifests at both the local and remote node.

Claims

1. A computer-implemented method, comprising, at a local node of a content-centric network in which a collection of content objects are represented in a local manifest:

receiving, by the local node, an advertisement corresponding to a remote manifest of a remote node of the content-centric network, the advertisement indicating a routable prefix of the remote manifest;

determining that the local node contains the local manifest indicating a same collection as the remote manifest, based on a routable prefix of the local manifest and the routable prefix of the remote manifest, wherein the local manifest represents a collection of content objects at the local node, includes corresponding hash values for the content objects, and further includes a root hash value which is an arithmetic sum of the hash values for the content objects, wherein each content object is a single piece of named data bound to a unique name that is location independent;

in response to determining that the root hash value of the local manifest is different from a root hash value of the remote manifest, sending a request for the remote manifest, wherein the request is an interest packet that includes a unique name of the remote manifest;

determining a set of content objects indicated in the remote manifest that are different from the content objects indicated in the local manifest; and

in response to transmitting a set of interests that includes the unique names for the different content objects, receiving the different content objects, which causes the local node to synchronize the collection represented by the local manifest with the collection represented by the remote manifest.

2. The method of claim 1, further comprising:

determining that the local manifest is different from the remote manifest.

3. The method of claim 1, wherein the sending the request for the remote manifest further comprises:

sending a set of interests based on a chunking protocol, and each interest corresponds to a numbered chunk of the remote manifest.

4. The method of claim 1, wherein the transmitting the set of interests for the different content objects is based on one or more of:

a hash value of a respective different content object; and

a name of the respective different content object as indicated in the remote manifest.

5. The method of claim 1, wherein a respective content object represented by the remote manifest or the local manifest has a name that is a hierarchically structured variable length identifier that comprises contiguous name components ordered from a most general level to a most specific level, and the name further indicates one or more of:

a time that the respective content object was modified; and

a sequence number based on a time that the respective content object was modified.

6. The method of claim 1, further comprising:

determining whether a respective content object represented by the remote manifest is more recent than a corresponding respective content object represented by the local manifest, based on one or more of;

a time that the respective content object represented by the remote manifest was modified, wherein a later time indicates a more recent version of the corresponding respective content object represented by the local manifest;

a sequence number based on a time that the respective content object represented by the remote manifest was modified, wherein a greater sequence number indicates a more recent version of the corresponding respective content object represented by the local manifest; and

an ordering of names of the content objects represented by the remote manifest, wherein an implicit sort order indicates a more recent version of the corresponding respective content object represented by the local manifest.

7. The method of claim 6, further comprising:

responsive to determining that the respective content object represented by the remote manifest is more recent than the corresponding respective content object represented by the local manifest, updating a value of the corresponding respective content object represented by the local manifest with a value of the respective content object represented by the remote manifest.

8. The method of claim 6, further comprising:

responsive to determining that the time the respective content object represented by the remote manifest was modified is less recent than a modified time of the corresponding respective content object represented by the local manifest, inserting a value and the time the respective content object represented by the remote manifest was modified into a history field of the corresponding respective content object represented by the local manifest.

9. The method of claim 1, wherein a packet sent or received by the local node indicates one or more of:

a routable prefix that identifies the remote manifest or the local manifest;

an identifier that the packet corresponds to a transfer of data;

the root hash value of the remote manifest or the local manifest;

a number corresponding to a numbered chunk of the remote manifest or the local manifest based on a chunking protocol;

a hash value of a respective content object represented by the remote manifest or the local manifest; and

a name of the respective content object represented by the remote manifest or the local manifest.

25. The method of claim 1, further comprising:

transmitting an advertisement for the local manifest to another remote node, which allows the other remote node to synchronize a remote manifest of the other remote node with the local manifest, wherein the local manifest and the remote manifest of the other remote node represent a same collection of content objects, thereby facilitating synchronization of collections between network nodes.

10. A computer-implemented method, comprising, at a local node of a content-centric network in which a collection of content objects are represented in a manifest:

transmitting, by the local node, an advertisement corresponding to the manifest, wherein the manifest represents the collection of content objects at the local node, the advertisement corresponds to an interest that indicates a root hash value of the manifest, and the root hash value is an arithmetic sum of the hash values for the content objects represented by the manifest, wherein each content object is a single piece of named data bound to a unique name that is location independent;

transmitting the manifest to a remote node of the content-centric network in response to receiving a request for the manifest;

receiving a request for a content object represented by the manifest, wherein the request is an interest packet that includes a unique name of the manifest; and

transmitting the content object to the remote node.

11. The method of claim 10, further comprising:

receiving a set of interests based on a chunking protocol, wherein a respective interest corresponds to a numbered chunk of the manifest.

12. The method of claim 10, wherein the interest indicates one or more of:

a routable prefix that identifies the manifest; and

an identifier that the interest advertises the manifest.

13. A non-transitory, computer-readable storage medium storing instructions that, when executed by a local node of a content-centric network in which a collection of content objects are represented in a local manifest, cause the local node to perform a method, the method comprising:

receiving an advertisement corresponding to a remote manifest of a remote node of the content-centric network, the advertisement indicating a routable prefix of the remote manifest;

determining that the local node contains the local manifest indicating a same collection as the remote manifest, based on a routable prefix of the local manifest and the routable prefix of the remote manifest, wherein the local manifest represents a collection of content objects at the local node, includes corresponding hash values for the content objects, and further includes a root hash value which is an arithmetic sum of the hash values for the content objects, wherein each content object is a single piece of named data bound to a unique name that is location independent;

in response to determining that the root hash value of the local manifest is different from a root hash value of the remote manifest, sending a request for the remote manifest, wherein the request is an interest packet that includes a unique name of the remote manifest;

determining a set of content objects indicated in the remote manifest that are different from the content objects indicated in the local manifest; and

in response to transmitting a set of interests that includes the unique names for the different content objects, receiving the different content objects, which causes the local node to synchronize the collection represented by the local manifest with the collection represented by the remote manifest.

14. The storage medium of claim 13, wherein the method further comprises:

determining that the local manifest is different from the remote manifest.

15. The storage medium of claim 13, wherein the sending the request for the remote manifest further comprises:

sending a set of interests based on a chunking protocol, and each interest corresponds to a numbered chunk of the remote manifest.

16. The storage medium of claim 13, wherein the transmitting the set of interests for the different content objects is based on one or more of:

a hash value of a respective different content object; and

a name of the respective different content object as indicated in the remote manifest.

17. The storage medium of claim 13, wherein a respective content object represented by the remote manifest or the local manifest has a name that is a hierarchically structured variable length identifier that comprises contiguous name components ordered from a most general level to a most specific level, and the name further indicates one or more of:

a time that the respective content object was modified; and

a sequence number based on a time that the respective content object was modified.

18. The storage medium of claim 13, wherein the method further comprises:

determining whether a respective content object represented by the remote manifest is more recent than a corresponding respective content object represented by the local manifest, based on one or more of;

a time that the respective content object represented by the remote manifest was modified, wherein a later time indicates a more recent version of the corresponding respective content object represented by the local manifest;

a sequence number based on a time that the respective content object represented by the remote manifest was modified, wherein a greater sequence number indicates a more recent version of the corresponding respective content object represented by the local manifest; and

an ordering of names of the content objects represented by the remote manifest, wherein an implicit sort order indicates a more recent version of the corresponding respective content object represented by the local manifest.

19. The storage medium of claim 18, wherein the method further comprises:

responsive to determining that the respective content object represented by the remote manifest is more recent than the corresponding respective content object represented by the local manifest, updating a value of the corresponding respective content object represented by the local manifest with a value of the respective content object represented by the remote manifest.

20. The storage medium of claim 18, wherein the method further comprises:

responsive to determining that the time the respective content object represented by the remote manifest was modified is less recent than a modified time of the corresponding respective content object represented by the local manifest, inserting a value and the time the respective content object represented by the remote manifest was modified into a history field of the corresponding respective content object represented by the local manifest.

21. The storage medium of claim 13, wherein a packet sent or received by the computer indicates one or more of:

a routable prefix that identifies the remote manifest or the local manifest;

an identifier that the packet corresponds to a transfer of data;

the root hash value of the remote manifest or the local manifest;

a number corresponding to a numbered chunk of the remote manifest or the local manifest based on a chunking protocol;

a hash value of a respective content object represented by the remote manifest or the local manifest; and

a name of the respective content object represented by the remote manifest or the local manifest.

22. A non-transitory, computer-readable storage medium storing instructions that, when executed by a local node of a content-centric network in which a collection of content objects are represented in a manifest, cause the local node to perform a method, the method comprising:

transmitting an advertisement corresponding to the manifest, wherein the manifest represents the collection of content objects at the computer, the advertisement corresponds to an interest that indicates a root hash value of the manifest, and the root hash value is an arithmetic sum of the hash values for the content objects represented by the manifest, wherein each content object is a single piece of named data bound to a unique name that is location independent;

transmitting the manifest to a remote node of the content-centric network in response to receiving a request for the manifest;

receiving a request for a content object represented by the manifest, wherein the request is an interest packet that includes a unique name of the manifest; and

transmitting the content object to the remote node.

23. The storage medium of claim 22, the method further comprising:

receiving a set of interests based on a chunking protocol, wherein a respective interest corresponds to a numbered chunk of the manifest.

24. The storage medium of claim 22, wherein the interest indicates one or more of:

a routable prefix that identifies the manifest; and

an identifier that the interest advertises the manifest.