SYSTEMS AND METHODS FOR CONTINUOUSLY AVAILABLE NETWORK FILE SYSTEM (NFS) STATE DATA

• US 20180165159A1
• Filed: 12/14/2016
• Published: 06/14/2018
• Est. Priority Date: 12/14/2016
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Baker, William Eugene, Shivam, Piyush
• Granted Patent: US 10,452,482 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 16/164 File meta data generation
• CPC Class Codes: G06F 16/183 Provision of network file services by network file servers, e.g. by using NFS, CIFS network file access protocols H04L67/1097
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/1097 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]

Abstract

According to some embodiments of the invention, systems and methods are provided for capturing and storing state information corresponding to various states of the network file system (NFS) for use in recovery during a system failure. In various aspects, the disclosed systems and methods may automatically collect and synchronously write state changes made to the NFS to non-volatile storage. In the event of an NFS system failure or crash (e.g., a failure of the NFS server), the state information corresponding to the NFS system may be automatically imported from the non-volatile storage, thereby enabling NFS services to be resumed immediately and transparently.

Claims

1. A method comprising:

receiving, by a network file system (NFS) server, instructions to change a state corresponding to a data object accessible by the NFS server from a current state to a new state;

storing, by the NFS server, an indication of the new state in volatile memory, the indication being stored in association with an identifier of the data object;

writing, by the NFS server, metadata representing the new state at a location in non-volatile storage, wherein the metadata is written in association with a same or different identifier of the data object;

detecting, by the NFS server, a failure involving the NFS server;

retrieving, by the NFS server, the metadata representing the new state from the location in the non-volatile storage; and

resuming service, by the NFS server, in accordance with the new state.

2. The method of claim 1, wherein the indication of the new state is erased from the volatile memory upon the failure involving the NFS server.

3. The method of claim 1, further comprising, after retrieving the metadata representing the new state from the location in the non-volatile storage:

repopulating at least some of the volatile memory to include the indication of the new state in association with the identifier of the data object.

4. The method of claim 1, wherein the new state includes at least one of an open state, a lock state, a client state, or a delegate state.

5. The method of claim 1, wherein the metadata representing the new state is written immediately in response to receiving the instructions to change the state corresponding to the data object.

6. The method of claim 1, wherein the metadata representing the new state retrieved from the non-volatile storage is included in a plurality of metadata representing a plurality of states of a plurality of data objects stored in the non-volatile storage, wherein the plurality of metadata is retrieved from the non-volatile storage, and wherein resuming service in accordance with the new state includes resuming service in accordance with the plurality of states.

7. The method of claim 1, wherein detecting the failure involving the NFS server includes determining that the indication of the new state is erased from the volatile memory.

8. A device comprising:

one or more processors; and

a non-transitory computer-readable medium containing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations including;

receiving instructions to change a state corresponding to a data object accessible by the NFS server from a current state to a new state;

storing an indication of the new state in volatile memory, the indication being stored in association with an identifier of the data object;

writing metadata representing the new state at a location in non-volatile storage, wherein the metadata is written in association with a same or different identifier of the data object;

detecting a failure involving the NFS server;

retrieving the metadata representing the new state from the location in the non-volatile storage; and

resuming service in accordance with the new state.

9. The device of claim 8, wherein the indication of the new state is erased from the volatile memory upon the failure involving the NFS server.

10. The device of claim 8, wherein the operations further include, after retrieving the metadata representing the new state from the location in the non-volatile storage:

repopulating at least some of the volatile memory to include the indication of the new state in association with the identifier of the data object.

11. The device of claim 8, wherein the new state includes at least one of an open state, a lock state, a client state, or a delegate state.

12. The device of claim 8, wherein the metadata representing the new state is written immediately in response to receiving the instructions to change the state corresponding to the data object.

13. The device of claim 8, wherein the metadata representing the new state retrieved from the non-volatile storage is included in a plurality of metadata representing a plurality of states of a plurality of data objects stored in the non-volatile storage, wherein the plurality of metadata is retrieved from the non-volatile storage, and wherein resuming service in accordance with the new state includes resuming service in accordance with the plurality of states.

14. The device of claim 8, wherein detecting the failure involving the NFS server includes determining that the indication of the new state is erased from the volatile memory.

15. A computer-program product tangibly embodied in a non-transitory machine-readable storage medium of a device, including instructions that, when executed by one or more processors, cause the one or more processors to:

receive instructions to change a state corresponding to a data object accessible by the NFS server from a current state to a new state;

store an indication of the new state in volatile memory, the indication being stored in association with an identifier of the data object;

write metadata representing the new state at a location in non-volatile storage, wherein the metadata is written in association with a same or different identifier of the data object;

detect a failure involving the NFS server;

retrieve the metadata representing the new state from the location in the non-volatile storage; and

resume service in accordance with the new state.

16. The computer-program product of claim 15, wherein the indication of the new state is erased from the volatile memory upon the failure involving the NFS server.

17. The computer-program product of claim 15, wherein the instructions further cause the one or more processors to, after retrieving the metadata representing the new state from the location in the non-volatile storage:

repopulate at least some of the volatile memory to include the indication of the new state in association with the identifier of the data object.

18. The computer-program product of claim 15, wherein the metadata representing the new state is written immediately in response to receiving the instructions to change the state corresponding to the data object.

19. The computer-program product of claim 15, wherein the metadata representing the new state retrieved from the non-volatile storage is included in a plurality of metadata representing a plurality of states of a plurality of data objects stored in the non-volatile storage, wherein the plurality of metadata is retrieved from the non-volatile storage, and wherein resuming service in accordance with the new state includes resuming service in accordance with the plurality of states.

20. The computer-program product of claim 15, wherein detecting the failure involving the NFS server includes determining that the indication of the new state is erased from the volatile memory.