Pull Model for File Replication at Multiple Data Centers

• US 20090083342A1
• Filed: 09/26/2007
• Published: 03/26/2009
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Corporation (NortonLifeLock Inc.)
• Inventors: Wong, Arthur, Tomic, George
• Granted Patent: US 8,019,727 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems

Abstract

Various embodiments of a system and method for replicating a file over multiple data centers are described. The method may comprise creating a plurality of file records in a database at a data center that initially receives the file. Each record may correspond to a destination data center at which the file should be stored. The file records may be replicated to respective databases at each of the destination data centers, and each respective destination data center may pull a copy of the file to the respective destination data center. When a file is pulled to a given destination data center, the file record corresponding to the copy of the file at the given destination data center may be updated, and the updated file record may be communicated to the other destination data centers.

Claims

1. A computer-accessible storage medium storing program instructions executable to implement a method comprising:

a first data center receiving a file and storing a first copy of the file;

the first data center determining that a second copy of the file should be stored at a second data center;

the first data center sending information regarding the file to the second data center;

in response to receiving the information regarding the file, the second data center writing information into a database at the second data center, wherein the information written to the database indicates that the file needs to be transmitted to the second data center to create the second copy of the file; and

the second data center initiating a transfer operation to transmit the file to the second data center to create the second copy of the file.

2. The computer-accessible storage medium of claim 1, wherein the method implemented by the program instructions further comprises:

after writing the information into the database at the second data center, the second data center querying the database to determine one or more files that need to be transmitted to the second data center;

wherein the second data center initiates the transfer operation to transmit the file to the second data center in response to the database query.

3. The computer-accessible storage medium of claim 1,

wherein the second data center periodically queries the database at the second data center to determine new files that need to be transmitted to the second data center.

4. The computer-accessible storage medium of claim 1,

wherein the second data center writing the information into the database at the second data center comprises the second data center writing into the database a first record corresponding to the first copy of the file at the first data center and a second record corresponding to the second copy of the file at the second data center;

wherein the second record indicates that the second copy of the file at the second data center has not yet been created.

5. The computer-accessible storage medium of claim 4, wherein the method implemented by the program instructions further comprises:

after the file is transmitted to the second data center, the second data center updating the second record in the database at the second data center to indicate that the second copy of the file has been created at the second data center.

6. The computer-accessible storage medium of claim 5, wherein the method implemented by the program instructions further comprises:

in response to receiving the file, the first data center writing into a database at the first data center a first record corresponding to the first copy of the file at the first data center and a second record corresponding to the second copy of the file at the second data center, wherein the second record indicates that the second copy of the file at the second data center has not yet been created;

after creating the second copy of the file at the second data center, the second data center sending information to the first data center indicating that the second copy of the file has been created at the second data center; and

in response to the information indicating that the second copy of the file has been created at the second data center, the first data center updating the second record in the database at the first data center to indicate that the second copy of the file has been created at the second data center.

7. The computer-accessible storage medium of claim 6, wherein the method implemented by the program instructions further comprises:

after the second record in the database at the first data center has been updated to indicate that the second copy of the file has been created at the second data center, a software application at the first data center requesting to access the file;

the first data center determining that the first copy of the file at the first data center is unavailable;

the first data center accessing the database at the first data center to determine that the second copy of the file is stored at the second data center; and

the first data center remotely accessing the second copy of the file stored at the second data center.

8. The computer-accessible storage medium of claim 1, wherein the method implemented by the program instructions further comprises:

after the information has been written into the database at the second data center but before the second copy of the file has been created at the second data center, a software application at the second data center requesting to access the file;

the second data center accessing the database at the second data center to determine that the first copy of the file is stored at the first data center; and

the second data center remotely accessing the first copy of the file stored at the first data center.

9. The computer-accessible storage medium of claim 1,

wherein the first data center determining that the second copy of the file should be stored at the second data center comprises:

the first data center determining one or more attributes of the file; and

the first data center querying a database at the first data center to determine one or more data centers at which the file should be stored based on the one or more attributes of the file.

10. The computer-accessible storage medium of claim 1, wherein the method implemented by the program instructions further comprises:

the first data center determining that a third copy of the file should be stored at a third data center;

the first data center sending information regarding the file to the third data center;

in response to receiving the information regarding the file, the third data center writing information into a database at the third data center, wherein the information written to the database indicates that the file needs to be transmitted to the third data center to create the third copy of the file; and

the third data center initiating a transfer operation to transmit the file to the third data center to create the third copy of the file.

11. The computer-accessible storage medium of claim 1,

wherein the second data center is coupled to the first data center through a network.

12. The computer-accessible storage medium of claim 1,

wherein the second data center initiating the transfer operation to transmit the file to the second data center to create the second copy of the file comprises the second data center initiating a transfer operation to transmit the file from the first data center to the second data center.

13. The computer-accessible storage medium of claim 1,

wherein the second data center initiating the transfer operation to transmit the file to the second data center to create the second copy of the file comprises the second data center initiating a transfer operation to transmit the file to the second data center from a data center other than the first data center.

14. A system comprising:

a plurality of computer systems at a plurality of data centers, wherein each computer system comprises one or more processors and memory storing program instructions;

wherein the program instructions stored in the memories of the computer systems are executable by the processors of the computer systems to implement a method comprising;

a first computer system at a first data center receiving a file and storing a first copy of the file;

the first computer system determining that a second copy of the file should be stored on a second computer system at a second data center;

the first computer system sending information regarding the file to the second computer system;

in response to receiving the information regarding the file, the second computer system writing information into a database at the second data center, wherein the information written to the database indicates that the file needs to be transmitted to the second computer system to create the second copy of the file; and

the second computer system initiating a transfer operation to transmit the file to the second computer system to create the second copy of the file.

15. The system of claim 14, wherein the method implemented by the program instructions further comprises:

after writing the information into the database at the second data center, the second computer system querying the database to determine one or more files that need to be transmitted to the second computer system;

wherein the second computer system initiates the transfer operation to transmit the file to the second computer system in response to the database query.

16. The system of claim 14,

wherein the second computer system writing the information into the database at the second computer system comprises the second computer system writing into the database a first record corresponding to the first copy of the file at the first computer system and a second record corresponding to the second copy of the file at the second computer system;

wherein the second record indicates that the second copy of the file at the second computer system has not yet been created.

17. The system of claim 16, wherein the method implemented by the program instructions further comprises:

after the file is transmitted to the second computer system, the second computer system updating the second record in the database at the second computer system to indicate that the second copy of the file has been created at the second computer system.

18. The system of claim 17, wherein the method implemented by the program instructions further comprises:

in response to receiving the file, the first computer system writing into a database at the first computer system a first record corresponding to the first copy of the file at the first computer system and a second record corresponding to the second copy of the file at the second computer system, wherein the second record indicates that the second copy of the file at the second computer system has not yet been created;

after creating the second copy of the file at the second computer system, the second computer system sending information to the first computer system indicating that the second copy of the file has been created at the second computer system; and

in response to the information indicating that the second copy of the file has been created at the second computer system, the first computer system updating the second record in the database at the first computer system to indicate that the second copy of the file has been created at the second computer system.

19. A method comprising:

a first data center receiving a file and storing a first copy of the file;

the first data center determining that a second copy of the file should be stored at a second data center;

the first data center sending information regarding the file to the second data center;

in response to receiving the information regarding the file, the second data center writing information into a database at the second data center, wherein the information written to the database indicates that the file needs to be transmitted to the second data center to create the second copy of the file; and

the second data center initiating a transfer operation to transmit the file to the second data center to create the second copy of the file.