SYSTEMS AND METHODS FOR PROVIDING NONLINEAR JOURNALING

• US 20110022790A1
• Filed: 09/30/2010
• Published: 01/27/2011
• Est. Priority Date: 08/18/2006
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Isilon Systems Incorporated (Dell Technologies Inc.)
• Inventors: Husted, Justin M., Passey, Aaron J., Godman, Peter J., Fachan, Neal T.
• Granted Patent: US 8,356,150 B2
• Time in Patent Office: Days
• US Class Current: 711/104
• CPC Class Codes: G06F 16/182 Distributed file systems

Abstract

In one embodiment, systems and methods are provided for nonlinear journaling. In one embodiment, groups of data designated for storage in a data storage unit are journaled into persistent storage. In one embodiment, the journal data is recorded nonlinearly. In one embodiment, a linked data structure records data and data descriptors in persistent storage.

Claims

1. A networked cluster of data storage nodes cooperating to execute transactions that are global to the networked cluster of data storage nodes, comprising:

a plurality of storage nodes of a distributed file system for storing files distributed in portions among two or more of the storage nodes, the plurality of storage nodes configured to communicate via a network, each storage node comprising;

a processor;

system memory;

at least one storage device configured to store the storage node'"'"'s respective portions of files stored in the distributed file system; and

persistent memory configured to store journal data; and

a plurality of journal modules, each one of said storage nodes having a different one of said plurality of journal modules associated therewith, wherein the journal module associated with each storage node is configured to record, in the associated persistent memory, journal data associated with the participation of the storage node in a global transaction, the global transaction including a write of a portion of a file to the storage node and a write of a different portion of the file to at least one other storage node, wherein the journal module associated with one of the plurality of storage nodes has only a portion of the information needed to recreate an entire global transaction and said journal module must cooperate with a journal module associated with at least one other storage node in order to recreate a global transaction;

wherein the recorded journal data can be used to recreate a transaction.

2. The networked cluster of data storage nodes of claim 1, wherein the at least one storage device comprises a hard-disk drive.

3. The networked cluster of data storage nodes of claim 1, wherein the system is configured to recreate the global transaction following a failure to at least one of said storage nodes.

4. The networked cluster of data storage nodes of claim 3, wherein a hard-disk drive of the at least one of said storage nodes is in an inconsistent state following the failure of the at least one of said storage nodes such that it is unclear whether data associated with the global transaction was written to a disk platter of the hard-disk drive of the at least one of said storage nodes.

5. The networked cluster of data storage nodes of claim 1, wherein said persistent memory is nonvolatile random access memory.

6. The networked cluster of data storage nodes of claim 1, wherein said data associated with said global transaction comprises information regarding transaction states and participant nodes cooperating in the global transaction.

7. The networked cluster of data storage nodes of claim 6, wherein the information regarding transaction states is recorded with atomic writes.

8. A processor-implemented method of journaling data associated with global transactions in a distributed data storage system, the computer-implemented method comprising:

journaling, by processor, data in persistent memory that is stored on a data storage unit in the distributed data storage system, the data storage unit comprising a processor and at least one storage device configured to store the data storage unit'"'"'s respective portions of files stored in the distributed data storage system, said data associated with said data storage unit'"'"'s participation in a transaction that is global to the distributed data storage system, the said transaction involving a write of a portion of a file to said associated data storage unit and a write of a different portion of the same file to at least one other data storage unit, wherein each data storage unit comprises a processor, persistent memory configured to store journal data, and at least one storage device;

wherein journaling said data comprises recording information sufficient to recreate the portion of the transaction corresponding to the associated data storage unit, wherein the journaled data associated with a single data storage unit has only a portion of the information needed to recreate a transaction that is global to the distributed data storage system, wherein said data storage unit must cooperate with at least one other data storage unit in order to recreate said transaction.

9. The processor-implemented method of claim 8, wherein journaling said data comprises recording information sufficient to recreate the transaction following a failure to at least one of the data storage units participating in the transaction.

10. The processor-implemented method of claim 9, wherein a hard-disk drive of the at least one of said data storage units is in an inconsistent state following the failure of the at least one of said storage units such that it is unclear whether data associated with the transaction was written to a disk platter of the hard-disk drive of the at least one of said data storage units.

11. The processor-implemented method of claim 8, wherein said persistent memory is nonvolatile random access memory on the data storage unit.

12. The processor-implemented method of claim 8, wherein said data associated with the transaction comprises information regarding transaction states and identities of data storage units cooperating in the transaction.

13. A computer-readable storage medium having instructions stored thereon for implementing, when the instructions are executed, a journal for data associated with global transactions in a distributed data storage system, the instructions comprising:

journaling data in persistent memory that is stored on a data storage unit in the distributed data storage system, the data storage unit comprising a processor and at least one storage device configured to store the data storage unit'"'"'s respective portions of files stored in the distributed data storage system, said data associated with said data storage unit'"'"'s participation in a transaction that is global to the distributed data storage system, said transaction involving cooperation of said data storage unit and at least one other data storage unit;

wherein journaling said data comprises recording information sufficient to recreate the portion of the transaction corresponding to the associated data storage unit, wherein the recorded journal data from each of the data storage units participating in the transaction can be collectively used to recreate the transaction.

14. The computer-readable storage medium of claim 13, wherein the transaction comprises a write of at least a portion of a file to the data storage unit and a portion of the file to at least one other data storage unit.

15. The computer-readable storage medium of claim 13, wherein the system is configured to recreate the transaction following a failure to at least one of said data storage units.

16. The computer-readable storage medium of claim 15, wherein a hard-disk drive of the at least one of said data storage units is in an inconsistent state following the failure of the at least one of said data storage units such that it is unclear whether data associated with the transaction was written to a disk platter of the hard-disk drive of the at least one of said data storage units.

17. The computer-readable storage medium of claim 13, wherein said data associated with said transaction comprises information regarding transaction states and identities of storage units cooperating in the transaction.