Systems and methods for providing variable protection

• US 8,054,765 B2
• Filed: 06/15/2009
• Issued: 11/08/2011
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Passey, Aaron J., Fachan, Neal T.
• Primary Examiner(s): Lai; Andrew
• Application Number:
  US12/484,905
• Publication Number:
  US 20090252066A1
• Time in Patent Office: 876 Days
• Field of Search: 370/217, 370/256, 370/379, 370/382, 370/408, 707/7, 707/100, 707/101, 707/103, 711/162, 714/36, 714/718
• US Class Current: 370/256
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes

Abstract

The systems and methods maintain varying protection levels of related objects, such as when nodes of a data structure are protected at the same or greater protection level as their children nodes. In one embodiment, the nodes store data to track protection levels of their children nodes.

Claims

1. A method of protecting nodes within a hierarchical data structure at variable protection levels, the hierarchical data structure comprising leaf nodes and non-leaf nodes, the method comprising:

determining a protection level for each of one or more leaf nodes, wherein each protection level corresponds to a level of protection against loss of data, and wherein each level of the protection against the loss of the data corresponds to at least one of a number of mirrored copies, a level of error correction, and a level of parity protection of the leaf node;

determining, by a computer processor, a protection level for a non-leaf node, wherein the non-leaf node has one or more children with corresponding protection levels, and wherein the protection level of the non-leaf node is based on a maximum of the protection levels of current children of the non-leaf node;

identifying an increase in the maximum of the protection levels of the current children of the non-leaf node;

as a result of identifying the increase in the maximum of the protection levels of the current children of the non-leaf node, determining, by a computer processor, an increased protection level for the non-leaf node; and

increasing at least one of a number of mirrored copies of the non-leaf node, a level of error correction of the non-leaf node, and a level of parity protection of the non-leaf node to correspond to the increased protection level for the non-leaf node.

2. The method of claim 1, further comprising:

storing the protection level for each of the one or more leaf nodes; and

storing the protection level for the non-leaf node.

3. The method of claim 1, wherein each of the one or more leaf nodes is associated with one or more sets of data, and determining the protection level for the each of the one or more leaf nodes is based on a maximum of the protection levels of the one or more sets of the data associated with the leaf nodes.

4. The method of claim 1, further comprising, for the non-leaf node, storing protection level information, the protection level information comprising the number of the current children of the non-leaf node having the protection level of the non-leaf node.

5. The method of claim 4, wherein the protection level information further comprises the number of the current children of the non-leaf node at each protection level other than the protection level of the non-leaf node.

6. A protection system for protecting data of variable protection levels, the system comprising:

at least one computer processor;

at least one memory;

a hierarchical data structure stored on the at least one memory and accessible by the at least one computer processor, the hierarchical data structure comprising leaf nodes and non-leaf nodes; and

at least one executable software module, the computer processor configured to execute the at least one executable software module, the at least one executable software module configured to;

determine protection levels for each of one or more of the leaf nodes;

determine a protection level for a non-leaf node, wherein the non-leaf node has one or more children with corresponding protection levels, wherein the protection level for the non-leaf node is based on a maximum of the protection levels of current children of the non-leaf node, wherein each protection level corresponds to a level of protection against loss of data, and wherein each level of the protection against the loss of the data corresponds to at least one of a number of mirrored copies, a level of error correction, and a level of parity protection of the leaf node;

identify an increase in the maximum of the protection levels of the current children of the non-leaf node; and

increase at least one of a number of mirrored copies of the non-leaf node, a level of error correction of the non-leaf node, and a level of parity protection of the non-leaf node to correspond to the identified increase in the maximum of the protection levels of the current children of the non-leaf node.

7. The system of claim 6, wherein the at least one executable software module is further configured to:

store a protection level indicator on the at least one memory for each of the leaf nodes; and

store a protection level indicator on the at least one memory for the non-leaf node.

8. The system of claim 6, wherein each of the leaf nodes is associated with one or more sets of data, and the at least one executable software module is further configured to determine the protection levels for each of the one or more leaf nodes based on a maximum of the protection levels of the one or more sets of the data associated with the leaf node.

9. The system of claim 6, wherein the at least one executable software module is further configured to, for the non-leaf node, store protection level information, the protection level information comprising the number of the current children of the non-leaf node having the protection level of the non-leaf node.

10. The system of claim 9, wherein the protection level information further comprises the number of the current children of the non-leaf node at each protection level other than the protection level of the non-leaf node.

11. A system for updating data stored using variable protection levels, the system comprising:

at least one computer processor;

at least one memory;

a hierarchical data structure stored on the at least one memory and accessible by the at least one computer processor, the hierarchical data structure comprising leaf nodes and non-leaf nodes, the leaf nodes comprising one or more references to one or more data sets; and

at least one executable software module, the computer processor configured to execute the at least one executable software module, the at least one executable software module configured to;

determine a first protection level of a leaf node based on a maximum of protection levels of the data sets referenced by the leaf node, wherein each protection level corresponds to a level of protection against loss of the data, and wherein each level of the protection against the loss of the data corresponds to at least one of a number of mirrored copies, a level of error correction, and a level of parity protection of the leaf node;

determine an increased protection level of an ancestor node of the leaf_node, wherein the ancestor node has one or more children with corresponding protection levels, and wherein the protection level of the ancestor node is based on a maximum of the protection levels of current children of the ancestor node; and

increase at least one of a number of mirrored copies of the ancestor node, a level of error correction of the ancestor node, and a level of parity protection of the ancestor node to correspond to the increased protection level of the ancestor node.

12. The system of claim 11, wherein the at least one executable software module is further configured to:

store a protection level indicator on the at least one memory for the leaf node; and

store a protection level indicator on the at least one memory for the ancestor node of the leaf node.

13. The system of claim 11, wherein the at least one executable software module is further configured to, for the ancestor node of the leaf node, store protection level information, the protection level information comprising the number of the current children of the ancestor node having the protection level of the ancestor node.

14. The system of claim 13, wherein the protection level information further comprises the number of the current children of the ancestor node at each protection level other than the protection level of the ancestor node.