Sharing state information among a plurality of file operation servers

• US 20070005603A1
• Filed: 06/29/2005
• Published: 01/04/2007
• Est. Priority Date: 06/29/2005
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Sedlar, Eric, Jain, Namit, Idicula, Sam, Agarwal, Nipun, Pannala, Syam, Kapoor, Vikram
• Granted Patent: US 7,809,675 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A method and apparatus for sharing state information among a plurality of servers is provided. A first server receives a request to perform a file operation, such as a NFS file system operation. Thereafter, the first server updates state information to reflect a change in state associated with processing the request. The first server then causes state update information, which identifies the change in state that was made at the first server, to be propagated to a second server. The second server updates state information, stored at the second server, to reflect the change in state associated with processing the request at the first server. Advantageously, a client may send a series of stateful file operations to either the first server or the second server, even if processing any one of the stateful file operation requests requires knowledge of the state of processing prior requests in the series of requests.

Claims

1. A machine-implemented method for sharing state information among a plurality of servers, comprising:

in response to receiving, at a first server of the plurality of servers, a request to perform a network file system (NFS) operation, updating first state information, stored at the first server, to reflect a change in state associated with processing the request;

propagating, from the first server to a second server of the plurality of servers, state update information that identifies the change in state; and

updating second state information, stored at the second server, to reflect the change in state associated with processing the request at the first server.

2. The method of claim 1, wherein each server, of the plurality of servers, is a database server.

3. The method of claim 1, wherein the step of propagating the state update information comprises:

the first server durably storing information identifying the change in state to a persistent storage; and

the second server reading the information identifying the change in state from the persistent storage.

4. The method of claim 1, wherein the step of propagating the state update information comprises:

transmitting, from a first volatile memory at the first server to a second volatile memory at the second server, information identifying the change in state.

5. The method of claim 1, further comprising:

after performing said step of updating said first state information, determining whether the change in state should be replicated at one or more servers of the plurality of servers, and

wherein said step of propagating said state update information is performed upon determining said change in state should be replicated at said second server.

6. The method of claim 1, wherein said step of propagating said state update information is performed for all changes in state, performed at said first server, as a result of processing NFS operations at said first server.

7. The method of claim 1, further comprising:

said second server receiving a second request, from a client, to perform a second NFS operation, wherein said client transmitted said request to said first server.

8. The method of claim 1, wherein the step of propagating the state update information comprises:

determining a priority associated with said change in state;

upon determining that said change in state has a first priority, performing the steps of;

the first server durably storing information identifying said change in state to a persistent storage, and

the second server reading the information identifying said change in state from the persistent storage; and

upon determining that said change in state has a second priority, performing the step of;

transmitting, from a first volatile memory at the first server to a second volatile memory at the second server, information identifying said change in state.

9. The method of claim 1, wherein the step of propagating said state update information comprises:

propagating, from the first server to each other server of the plurality of servers, said state update information.

10. A machine-readable medium carrying one or more sequences of instructions for sharing state information among a plurality of servers, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

in response to receiving, at a first server of the plurality of servers, a request to perform a network file system (NFS) operation, updating first state information, stored at the first server, to reflect a change in state associated with processing the request;

propagating, from the first server to a second server of the plurality of servers, state update information that identifies the change in state; and

updating second state information, stored at the second server, to reflect the change in state associated with processing the request at the first server.

11. The machine-readable medium of claim 10, wherein each server, of the plurality of servers, is a database server.

12. The machine-readable medium of claim 10, wherein the step of propagating the state update information comprises:

the first server durably storing information identifying the change in state to a persistent storage; and

the second server reading the information identifying the change in state from the persistent storage.

13. The machine-readable medium of claim 10, wherein the step of propagating the state update information comprises:

transmitting, from a first volatile memory at the first server to a second volatile memory at the second server, information identifying the change in state.

14. The machine-readable medium of claim 10, wherein execution of the one or more sequences of instructions by the one or more processors further causes the one or more processors to perform the steps of:

after performing said step of updating said first state information, determining whether the change in state should be replicated at one or more servers of the plurality of servers, and

wherein said step of propagating said state update information is performed upon determining said change in state should be replicated at said second server.

15. The machine-readable medium of claim 10, wherein said step of propagating said state update information is performed for all changes in state, performed at said first server, as a result of processing NFS operations at said first server.

16. The machine-readable medium of claim 10, wherein execution of the one or more sequences of instructions by the one or more processors further causes the one or more processors to perform the step of:

said second server receiving a second request, from a client, to perform a second NFS operation, wherein said client transmitted said request to said first server.

17. The machine-readable medium of claim 10, wherein the step of propagating the state update information comprises:

determining a priority associated with said change in state;

upon determining that said change in state has a first priority, performing the steps of;

the first server durably storing information identifying said change in state to a persistent storage, and

the second server reading the information identifying said change in state from the persistent storage; and

upon determining that said change in state has a second priority, performing the step of;

transmitting, from a first volatile memory at the first server to a second volatile memory at the second server, information identifying said change in state.

18. The machine-readable medium of claim 10, wherein the step of propagating said state update information comprises:

propagating, from the first server to each other server of the plurality of servers, said state update information.