ACTIVITY-BASED BLOCK MANAGEMENT OF A CLUSTERED FILE SYSTEM USING CLIENT-SIDE BLOCK MAPS

• US 20130046890A1
• Filed: 08/15/2011
• Published: 02/21/2013
• Est. Priority Date: 08/15/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Adkins, Janet, Brandyberry, Matthew T., Palsule, Ninad
• Granted Patent: US 9,009,205 B2
• Time in Patent Office: Days
• US Class Current: 709/226
• CPC Class Codes: G06F 16/1824 implemented using Network-attached Storage [NAS] architecture distributed or networked storage systems G06F3/067; protocols for distributed storage of data in a network H04L67/1097
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067
• CPC Class Codes: H04L 12/6418 Hybrid transport
• 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

A technique for operating a client node in a clustered file system includes allocating a number of blocks during a first time window and tracking the number of blocks allocated during the first time window. The technique further includes transmitting a block allocation request to a server node of the clustered file system for a number of requested blocks in response to a number of free blocks in a client-side block map reaching a first threshold value. In this case, the number of the requested blocks is based on the number of blocks allocated by the client node during the first time window.

Claims

1. A method of operating a client node in a clustered file system, the method comprising:

allocating, by the client node, a number of blocks during a first time window;

tracking, by the client node, the number of blocks allocated by the client node during the first time window; and

transmitting, from the client node, a block allocation request to a server node of the clustered file system for a number of requested blocks in response to a number of free blocks in a client-side block map reaching a first threshold value, wherein the number of the requested blocks is based on the number of blocks allocated by the client node during the first time window.

2. The method of claim 1, wherein the first threshold value is based on the number of the requested blocks.

3. The method of claim 1, further comprising:

receiving, at the client node, a client-side block map revocation message from the server node; and

in response to receiving the client-side block map revocation message, transmitting, from the client node, one or more extent messages to the server node, wherein the one or more extent messages each provide a contiguous set of blocks specified by a start block and a length that the client node is returning to the server node.

4. The method of claim 3, further comprising:

transmitting, from the client node, a client-side block map response message to the server node of the clustered file system following transmission of a last one of the one or more extent messages, wherein the client-side block map response message indicates all blocks maintained by the client-side block map have been returned to the server node.

5. The method of claim 1, further comprising:

initiating a block return from the client-side block map to the server node in response to the number of the requested blocks converging to zero and the free blocks in the client-side block map being greater than a minimum value.

6. A method of operating a server node in a clustered file system, the method comprising:

tracking, at the server node, a number of free blocks in the clustered file system; and

transmitting, from the sever node, a client-side block map revocation message to one or more client nodes of the clustered file system in response the number of the free blocks in the clustered file system falling below a first threshold value.

7. The method of claim 6, wherein the client-side block map revocation message is broadcast to all of the client nodes in the clustered file system.

8. The method of claim 6, wherein the client-side block map revocation message is only transmitted to the client nodes in the clustered file system that are currently maintaining a client-side block map.

9. The method of claim 6, wherein the client-side block map revocation message only applies to a client-side block map for a specific storage tier.

10. The method of claim 6, further comprising:

transmitting, from the sever node, a client-side block map initiation message to a first one of the client nodes of the clustered file system in response to the number of the free blocks in the clustered file system increasing above a second threshold value and receipt of a block allocate message from the first one of the client nodes.

11. A client node of a clustered file system, the client node comprising:

a data storage subsystem; and

a processor coupled to the data storage subsystem, wherein the processor is configured to;

allocate a number of blocks during a first time window;

track the number of blocks allocated during the first time window; and

transmit a block allocation request to a server node of the clustered file system for a number of requested blocks in response to a number of free blocks in a client-side block map reaching a first threshold value, wherein the number of the requested blocks is based on the number of blocks allocated by the client node during the first time window.

12. The client node of claim 11, wherein the first threshold value is based on the number of the requested blocks.

13. The client node of claim 11, wherein the processor is further configured to:

receive a client-side block map revocation message from the server node; and

in response to receiving the client-side block map revocation message, transmit one or more extent messages to the server node, wherein the one or more extent messages each provide a contiguous set of blocks specified by a start block and a length that the client node is returning to the server node.

14. The client node of claim 13, wherein the processor is further configured to:

transmit a client-side block map response message to the server node of the clustered file system following transmission of a last one of the one or more extent messages, wherein the client-side block map response message indicates all blocks maintained by the client-side block map have been returned to the server node.

15. The client node of claim 11, wherein the processor is further configured to:

initiate a block return from the client-side block map to the server node in response to the number of the requested blocks converging to zero and the free blocks in the client-side block map being greater than a minimum value.

16. A server node of a clustered file system, the server node comprising:

a data storage subsystem; and

a processor coupled to the data storage subsystem, wherein the processor is configured to;

track a number of free blocks in the clustered file system; and

transmit a client-side block map revocation message to one or more client nodes of the clustered file system in response the number of the free blocks in the clustered file system falling below a first threshold value.

17. The server node of claim 16, wherein the client-side block map revocation message is broadcast to all of the client nodes in the clustered file system.

18. The server node of claim 16, wherein the client-side block map revocation message is only transmitted to the client nodes in the clustered file system that are currently maintaining a client-side block map.

19. The server node of claim 16, wherein the client-side block map revocation message only applies to a client-side block map for a specific storage tier.

20. The server node of claim 16, wherein the processor is further configured to:

transmit a client-side block map initiation message to a first one of the client nodes of the clustered file system in response to the number of the free blocks in the clustered file system increasing above a second threshold value and receipt of a block allocate message from the first one of the client nodes.