System and method for data retention in a decentralized system

1. A node for use in a data management system, comprising:

a persistent storage that stores data; and

a data protection agent programmed to:

make an identification of a data protection strategy change event for the data;

in response to the identification:

make a determination that the data protection strategy change event is a scale down event;

in response to the determination:

identify a number of replicas of the data in other nodes that are in a predetermined state;

make a second determination that the number of the replicas of the data in the other nodes that are in the predetermined state exceeds a threshold specified by a data protection policy associated with the data protection strategy change event; and

reduce the number of replicas that exceed the threshold to be less than the threshold in response to the second determination.

2. The node of claim 1 , wherein reducing the number of replicas that exceed the threshold to be less than the threshold comprises:

sending a scale down command to at least one of the number of the replicas that exceeds the threshold,

wherein the scale down command specifies the data.

3. The node of claim 1 , wherein the data protection agent is further programmed to:

make an second identification of a second data protection strategy change event for the data;

in response to the second identification:

make a third determination that the second data protection strategy change event is a global deletion event;

in response to the third determination:

identify a portion of the other nodes that advertise that each respective node of the portion of the nodes stores a replica of the data; and

remove all replicas of the data from the identified portion of the other nodes.

4. The node of claim 3 , wherein removing all replicas of the data from the identified portion of the other nodes:

sending a global deletion request to each of the nodes of the identified portion of the other nodes.

5. The node of claim 1 , wherein the data protection agent is further programmed to:

obtain a state verification request for a state of second data;

make a third determination that the second data is stored in the persistent storage;

indicate that the state is acceptable based on the third determination and in response to the state verification request.

6. The node of claim 5 , wherein the data protection agent is further programmed to:

obtain a second scale down request for the second data;

in response to obtaining the second scale down request:

delete the second data to obtain deleted second data; and

update metadata associated with the deleted second data to specify:

an identifier of the second data, and

that the second data is available; and

advertise that the second data is available after deleting the second data.

7. The node of claim 6 , wherein the data protection agent is further programmed to:

after deleting the second data:

obtain a second state verification request for the state of the second data;

make a fourth determination that the second data is not stored in the persistent storage in response to obtaining the second state verification request;

make a fifth determination that the updated metadata associated with the deleted second data specifies that the second data is available in response to the fourth determination; and

indicate that the state is acceptable based on the fifth determination and in response to the second state verification request.

8. A method for managing a node in a data management system, comprising:

making an identification of a data protection strategy change event for data in a persistent storage of the node;

in response to the identification:

making a determination that the data protection strategy change event is a scale down event;

in response to the determination:

identifying a number of replicas of the data in other nodes that are in a predetermined state;

making a second determination that the number of the replicas of the data in the other nodes that are in the predetermined state exceeds a threshold specified by a data protection policy associated with the data protection strategy change event; and

reducing the number of replicas that exceed the threshold to be less than the threshold in response to the second determination.

9. The method of claim 8 , wherein reducing the number of replicas that exceed the threshold to be less than the threshold comprises:

sending a scale down command to at least one of the number of the replicas that exceeds the threshold,

wherein the scale down command specifies the data.

10. The method of claim 8 , further comprising:

making a second identification of a second data protection strategy change event for the data;

in response to the second identification:

making a third determination that the second data protection strategy change event is a global deletion event;

in response to the third determination:

identifying a portion of the other nodes that advertise that each respective node of the portion of the nodes stores a replica of the data; and

removing all replicas of the data from the identified portion of the other nodes.

11. The method of claim 10 , wherein removing all replicas of the data from the identified portion of the other nodes:

sending a global deletion request to each of the nodes of the identified portion of the other nodes.

12. The method of claim 8 , further comprising:

obtaining a state verification request for a state of second data;

making a third determination that the second data is stored in the persistent storage;

indicating that the state is acceptable based on the third determination and in response to the state verification request.

13. The method of claim 12 , further comprising:

obtaining a second scale down request for the second data;

in response to obtaining the second scale down request:

deleting the second data to obtain deleted second data; and

updating metadata associated with the deleted second data to specify:

an identifier of the second data, and

that the second data is available; and

advertise that the second data is available after deleting the second data.

14. The method of claim 13 , further comprising:

after deleting the second data:

obtaining a second state verification request for the state of the second data;

making a fourth determination that the second data is not stored in the persistent storage in response to obtaining the second state verification request;

making a fifth determination that the updated metadata associated with the deleted second data specifies that the second data is available in response to the fourth determination; and

indicating that the state is acceptable based on the fifth determination and in response to the second state verification request.

15. A non-transitory computer readable medium comprising computer readable program code, which when executed by a computer processor enables the computer processor to perform a method for managing a node in a data management system, the method comprising:

making an identification of a data protection strategy change event for data in a persistent storage of the node;

in response to the identification:

making a determination that the data protection strategy change event is a scale down event;

in response to the determination:

identifying a number of replicas of the data in other nodes that are in a predetermined state;

making a second determination that the number of the replicas of the data in the other nodes that are in the predetermined state exceeds a threshold specified by a data protection policy associated with the data protection strategy change event; and

reducing the number of replicas that exceed the threshold to be less than the threshold in response to the second determination.

16. The non-transitory computer readable medium of claim 15 , wherein reducing the number of replicas that exceed the threshold to be less than the threshold comprises:

sending a scale down command to at least one of the number of the replicas that exceeds the threshold,

wherein the scale down command specifies the data.

17. The non-transitory computer readable medium of claim 15 , wherein the method further comprises:

making a second identification of a second data protection strategy change event for the data;

in response to the second identification:

making a third determination that the second data protection strategy change event is a global deletion event;

in response to the third determination:

identifying a portion of the other nodes that advertise that each respective node of the portion of the nodes stores a replica of the data; and

removing all replicas of the data from the identified portion of the other nodes.

18. The non-transitory computer readable medium of claim 17 , wherein removing all replicas of the data from the identified portion of the other nodes:

sending a global deletion request to each of the nodes of the identified portion of the other nodes.

19. The non-transitory computer readable medium of claim 15 , wherein the method further comprises:

obtaining a state verification request for a state of second data;

making a third determination that the second data is stored in the persistent storage;

indicating that the state is acceptable based on the third determination and in response to the state verification request.

20. The non-transitory computer readable medium of claim 19 , wherein the method further comprises:

obtaining a second scale down request for the second data;

in response to obtaining the second scale down request:

deleting the second data to obtain deleted second data; and

updating metadata associated with the deleted second data to specify:

an identifier of the second data, and

that the second data is available; and

advertise that the second data is available after deleting the second data.