METHODS AND SYSTEMS TO MAINTAIN DATA COHERENCY

• US 20120109912A1
• Filed: 10/28/2010
• Published: 05/03/2012
• Est. Priority Date: 10/28/2010
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Inventors: Donze, Fabian, Sengupta, Debabrata
• Granted Patent: US 9,531,597 B2
• Time in Patent Office: Days
• US Class Current: 707/694
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies

Abstract

In one embodiment, a data coherency system access an age criterion associated with a data set and determines a previous refresh time associated with the data set. The data coherency defines a next refresh time that satisfies the age criterion relative to the previous refresh time and schedules a request for the data set at the next refresh time.

Claims

1. A processor-readable medium storing code representing instructions to cause a processor to perform a process, the process comprising:

accessing an age criterion associated with a data set;

determining a previous refresh time associated with the data set;

defining a next refresh time that satisfies the age criterion relative to the previous refresh time; and

scheduling a request for the data set at the next refresh time.

2. The processor-readable medium of claim 1, the process further comprising:

determining a refresh deadline time based on the age criterion and the previous refresh time, the next refresh time being before the refresh deadline time.

3. The processor-readable medium of claim 1, wherein the age criterion is a maximum age criterion included within a data refresh policy associated with a computing device, the process further comprising:

accessing a minimum age criterion associated with the data set and included within the data refresh policy, the next refresh time satisfies the maximum age criterion relative to the previous refresh time and the minimum age criterion relative to the previous refresh time.

4. The processor-readable medium of claim 1, wherein the next refresh time is a first next refresh time and the request for the data set is a first request for the data set, the process further comprising:

executing the first request for the data set at the first next refresh time;

determining that the data set was not received in response to the first request for the data set;

defining a second next refresh time; and

scheduling a second request for the data set at the second next refresh time.

5. The processor-readable medium of claim 1, wherein the next refresh time is a first next refresh time and the request for the data set is a first request for the data set, the process further comprising:

executing the first request for the data set at the first next refresh time;

determining that the data set was not received in response to the first request for the data set;

defining a second next refresh time that satisfies the age criterion relative to the previous refresh time; and

scheduling a second request for the data set at the second next refresh time.

6. The processor-readable medium of claim 1, wherein the next refresh time is a first next refresh time and the request for the data set is a first request for the data set, the process further comprising:

requesting the data set at the first next refresh time;

determining that the data set was not received in response to the request for the data set;

defining a second next refresh time that satisfies the age criterion relative to the previous refresh time; and

scheduling a request for the data set at the second next refresh time, a first period defined by the previous request time and the first next refresh time different from a second period defined by the first next refresh time and the second next refresh time.

7. The processor-readable medium of claim 1, the process further comprising:

determining, before the defining the next refresh time, that a candidate next refresh time before the next refresh time is within a blackout period; and

discarding the candidate next refresh time.

8. The processor-readable medium of claim 1, the process further comprising:

determining, before the defining the next refresh time, that a candidate next refresh time before the next refresh time is at a time period associated with a failed request for the data set; and

discard the candidate next refresh time.

9. A data coherency system, comprising:

a request schedule module configured to;

access, in response to the information associated with addition of a device to a communications network, a data refresh policy from a plurality of data refresh policies based on an attribute of the device,

schedule, at a first time, a first request for a data set associated with the device at a first next refresh time based on an age criterion of the accessed data refresh policy,

determine, after the first next request time, that the data set was not received in response to the first request for the data set,

schedule, at a second time, a second request for the data set at a second next refresh time,

wherein a first period defined by the first time and the first next refresh time is different from a second period defined by the second time and the second next refresh time.

10. The system of claim 9, wherein the first period is greater than the second period.

11. The system of claim 9, wherein the first period is at least two times greater than the second period.

12. The system of claim 9, wherein:

the request schedule module is configured to determine, after the second next refresh time, that the data set was not received in response to the second request for the data set;

the request schedule module is configured to schedule, at a third time, a third request for the data set at a third next refresh time,

a third period defined by the third time and the third next refresh time being different from the first period and from the second period.

13. The system of claim 9, wherein the attribute is associated with a component of the device.

14. The system of claim 9, wherein the attribute is associated with a capability of the device.

15. The system of claim 9, wherein the device discovery module is configured to communicate with the device via a communications link of the communications network.

16. The system of claim 9, wherein the request schedule module is configured to determine, before first time, that the first next request time is not included within a blackout period.

17. A method to maintain data coherency, comprising:

accessing a data refresh policy from a plurality of data refresh policies based on a data set identifier associated with the data refresh policy, each data refresh policy from the plurality of data refresh policies including an age criterion;

defining a first next refresh time for a first request for a data set associated with the data set identifier based on the age criterion of the data refresh policy such that the first next refresh time satisfies the age criterion and is not included within a blackout period;

determining that the data set was not received at the first next refresh time; and

defining a second next refresh time for a second request for the data set based on the age criterion of the data refresh policy such that the second next refresh time satisfies the age criterion of the data refresh policy.

18. The method of claim 17, further comprising:

determining that the first next refresh time is not included within any blackout period from a plurality of blackout periods described within the data refresh policy, the blackout period included within the plurality of blackout periods.

19. The method of claim 17, further comprising:

determining that the first next refresh time is not included within any blackout period from a plurality of blackout periods, the blackout period included within the plurality of blackout periods; and

determining that the second next refresh time is not included within any blackout period from the plurality of blackout periods.

20. The method of claim 17, further comprising:

receiving a notification associated with a new device within a communications network, the accessing being in response to the receiving.