FILE CHANGE NOTIFICATIONS IN A SCALE-OUT NAS SYSTEM

• US 20140280500A1
• Filed: 09/30/2013
• Published: 09/18/2014
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Sahlberg, Ronnie Leif, Ambach, Christian Markus Michael
• Granted Patent: US 9,456,026 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• 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

A method for file change notifications includes creating, on a first local node, a file change notification message in response to a client creating, deleting, and/or modifying a file system item addressed through a file path. The first local node notifies associated local client processes representing clients connected to the first local node and flagged to receive file change information. The notification message includes information regarding a file change for the file path. The method includes checking a global node for second local nodes flagged to receive file change information for the file path and sending a file change notification message from the first local node to the second local nodes in response to receiving identification of the second local nodes. A second local node notifies associated local client processes representing clients connected to a second local node and flagged to receive file change information for the file path.

Claims

1. A method comprising:

creating, on a first local node, a file change notification message in response to a client one or more of creating, deleting, and modifying a file system item addressed through a file path, the first local node sending the file change notification message to one or more local client processes flagged to receive file change information for the file path, wherein a local client process is associated with the first local node and represents a client connected to the first local node and wherein the file change notification message comprises information regarding a file change for the file path;

checking a global node for one or more second local nodes flagged to receive file change information for the file path, the one or more second local nodes different than the first local node; and

sending a file change notification message from the first local node to the one or more second local nodes in response to receiving identification of the one or more second local nodes flagged to receive file change information for the file path, a second local node sending a file change notification message to one or more local client processes flagged to receive file change information for the file path, the one or more local client processes associated with the second local node and being different than the one or more local client processes associated with the first local node wherein a local client process represents a client connected to a second local node.

2. The method of claim 1, wherein one or more local nodes store file change notification information and the global node stores identification of the one or more second local nodes flagged to receive file change information, wherein the first local node sends the file change notification message to the one or more second local nodes without sending the file change notification message to the global node.

3. The method of claim 1, wherein the global node stores identification of the one or more second local nodes flagged to receive file change information without storing one or more of file change notification information and local client process information associated with the file change notification information.

4. The method of claim 1, further comprising flagging a local client process to receive file change information for a file path in response to the local client process sending a file change notification request to an associated local node without sending a file change notification request to the global node, wherein flagging a local client process to receive file change information comprises storing notification information associated with the local client process on a data store of the local node without storing the notification information on a data store of the global node, the notification information comprising one or more of a file path, a local client process identifier, and one or more local client process attributes.

5. The method of claim 1, further comprising flagging a local node to receive file change information for a file path in response to a local client process associated with the local node being flagged to receive file change information for the file path, the local client process being the first local client process flagged to receive file change information for the file path, wherein flagging a local node to receive file change information comprises storing identification information associated with the local node on a data store of the global node, the identification information comprising one or more of a file path, a local node name, and a local node number.

6. The method of claim 1, further comprising unflagging a local client process from receiving file change information for the file path in response to the local client process sending an unflag request to an associated local node without sending an unflag request to the global node.

7. The method of claim 1, further comprising unflagging a local node from receiving file change information for a file path in response to a local client process associated with the local node unflagging from receiving file change information for the file path, the local client process being the last local client process unflagged to receive file change information for the file path.

8. The method of claim 7, wherein unflagging a local client process comprises deleting notification information regarding the local client process from the local data store of the local node and wherein unflagging a local node comprises deleting identification information regarding the local node from the global data store of the global node.

9. The method of claim 8, wherein deleting one or more of notification information from the local data store and identification information from the global data store comprises marking the information as deleted wherein deleting the information occurs after the expiration of a predetermined period of time.

10. The method of claim 1, wherein a second local node comprises a local proxy process, wherein the local proxy process receives a file change notification message from a first local node and sends the file change notification message to one or more local client processes flagged to receive file change information in response to receiving identification of one or more local client processes flagged to receive file change information.

11. The method of claim 1, further comprising sending a file change notification message to one or more second local nodes having one or more local client processes flagged to receive file change information for every parent directory in the file path.

12. The method of claim 1, wherein the first local node, the global node, and the one or more second local nodes communicate over a network protocol, the network protocol comprising a server message block protocol.

13. A computer program product for file notifications in a scale-out network-attached storage system, the computer program product comprising a computer readable storage medium having program code embodied therein, the program code readable/executable by a processor to:

create, on a first local node, a file change notification message in response to a client one or more of creating, deleting, and modifying a file system item addressed through a file path, the first local node sending the file change notification message to one or more local client processes flagged to receive file change information for the file path, wherein a local client process is associated with the first local node and represents a client connected to the first local node and wherein the file change notification message comprises information regarding a file change for the file path;

check a global node for one or more second local nodes flagged to receive file change information for the file path, the one or more second local nodes different than the first local node; and

send a file change notification message from the first local node to the one or more second local nodes in response to receiving identification of the one or more second local nodes flagged to receive file change information for the file path, a second local node sending a file change notification message to one or more local client processes flagged to receive file change information for the file path, the one or more local client processes associated with the second local node and being different than the one or more local client processes associated with the first local node wherein a local client process represents a client connected to a second local node.

14. The computer program product of claim 13, wherein one or more local nodes store file change notification information and the global node stores identification of the one or more second local nodes flagged to receive file change information, wherein the first local node sends the file change notification message to the one or more second local nodes without sending the file change notification message to the global node.

15. The computer program product of claim 13, wherein the global node stores identification of the one or more second local nodes flagged to receive file change information without storing one or more of file change notification information and local client process information associated with the file change notification information.

16. The computer program product of claim 13, further comprising flagging a local client process to receive file change information for a file path in response to the local client process sending a file change notification request to an associated local node without sending a file change notification request to the global node, wherein flagging a local client process to receive file change information comprises storing notification information associated with the local client process on a data store of the local node without storing the notification information on a data store of the global node, the notification information comprising one or more of a file path, a local client process identifier, and one or more local client process attributes.

17. The computer program product of claim 13, further comprising flagging a local node to receive file change information for a file path in response to a local client process associated with the local node being flagged to receive file change information for the file path, the local client process being the first local client process flagged to receive file change information for the file path, wherein flagging a local node to receive file change information comprises storing identification information associated with the local node on a data store of the global node, the identification information comprising one or more of a file path, a local node name, and a local node number.

18. The computer program product of claim 13, further comprising unflagging a local client process from receiving file change information for the file path in response to the local client process sending an unflag request to an associated local node without sending an unflag request to the global node.

19. The computer program product of claim 13, further comprising unflagging a local node from receiving file change information for a file path in response to a local client process associated with the local node unflagging from receiving file change information for the file path, the local client process being the last local client process unflagged to receive file change information for the file path.

20. The computer program product of claim 19, wherein unflagging a local client process comprises deleting notification information regarding the local client process from the local data store of the local node and wherein unflagging a local node comprises deleting identification information regarding the local node from the global data store of the global node and wherein deleting one or more of notification information from the local data store and identification information from the global data store comprises marking the information as deleted wherein deleting the information occurs after the expiration of a predetermined period of time.