Method and apparatus for using a USB cable as a cluster quorum device

• US 7,359,959 B2
• Filed: 01/05/2005
• Issued: 04/15/2008
• Est. Priority Date: 08/23/2004
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Faipot, Laurent, Mazzilli, Jean-Pascal, Lizzi, Christophe
• Primary Examiner(s): Myers; Paul R.
• Application Number:
  US11/029,709
• Publication Number:
  US 20060041778A1
• Time in Patent Office: 1,196 Days
• Field of Search: 709/221, 710/110
• US Class Current: 709/221
• CPC Class Codes: G06F 13/102 where the programme performs an interfacing function, e.g. device driver G06F13/105 takes precedence; scheduling within device drivers G06F9/52; contention policies within device drivers G06F9/4881
• CPC Class Codes: G06F 2213/0042 Universal serial bus [USB]

Abstract

A method for obtaining a quorum vote by a first node using a Universal Serial Bus (USB) quorum cable, wherein the USB quorum cable comprises a first end connected to a first node and a second end connected to a second node, including determining whether the USB quorum cable is reserved by the second node by querying a memory located in the USB quorum cable, if the USB quorum cable is not reserved by the second node attempting to reserve the USB quorum cable, determining whether the attempt to reserve the USB quorum cable was successful, and obtaining the quorum vote by the first node, if the attempt to reserve the USB quorum cable is successful.

Claims

1. A method for obtaining a quorum vote comprising:

determining that a network connection between a first node and a second node is inactive, wherein the network connection is associated with a local area network;

determining, by the first node, whether a Universal Serial Bus (USB) quorum cable is reserved by the second node by querying a memory embedded in the USB quorum cable, wherein the USB quorum cable comprises a first end connected to the first node and a second end connected to the second node; and

if the USB quorum cable is not reserved by the second node, the first node;

attempting to reserve the USB quorum cable;

determining whether the attempt to reserve the USB quorum cable was successful; and

obtaining the quorum vote if the attempt to reserve the USB quorum cable is successful, wherein the quorum vote is obtained without direct communication between the first node and the second node,

attempting to create a cluster using the quorum vote, wherein the cluster comprises the first node.

2. The method of claim 1, wherein determining whether the USB quorum cable is reserved by the second node comprises:

sending a read request to the memory located in the USB quorum cable to obtain a status of the USB quorum cable.

3. The method of claim 2, wherein the memory is an EEPROM.

4. The method of claim 2, wherein the read request is communicated to the USB quorum cable using a first-in-first-out queue located in the USB quorum cable and operatively connected to the first node.

5. The method of claim 1, wherein the attempt to reserve the USB quorum cable is successful if a stats of the USB quorum cable indicates that the first node has reserved the USB quorum cable.

6. A cluster comprising:

a Universal Serial Bus (USB) quorum cable having a first end and a second end;

a first node connected to the first end; and

a second node connected to the second end,

wherein the first node and the second node are connected over a local area network;

wherein the first node and the second node comprise functionality to reserve the USB quorum cable, thereby obtaining a quorum vote, wherein the quorum vote is obtained without direct communication between the first node and the second node, and

wherein the USB quorum cable further comprises a memory that stores a status of the USB quorum cable,

wherein the first node includes functionality to attempt to create the cluster when the first node reserves the quorum vote, wherein the cluster comprises the first node, and

wherein the second node includes functionality to attempt to create the cluster when the second node reserves the quorum vote.

7. The cluster of claim 6, wherein functionality to reserve the USB quorum cable by the first node comprises functionality to:

determine whether the USB quorum cable is reserved by the second node by querying the memory comprised in the USB quorum cable; and

if the USB quorum cable is not reserved by the second node;

attempt to reserve the USB quorum cable;

determine whether the attempt to reserve the USB quorum cable was successful; and

obtain the quorum vote by the first node, if the attempt to reserve the USB quorum cable is successful.

8. The cluster of claim 7, wherein determining whether the USB quorum cable is reserved by the second node comprises:

sending a read request to the memory comprised in the USB quorum cable to obtain the status of the USB quorum cable.

9. The cluster of claim 8, wherein the read request is communicated to the USB quorum cable using a first-in-first-out queue located in the USB quorum cable and operatively connected to the first node.

10. The cluster of claim 9, wherein the attempt to reserve the USB quorum cable is successful if the status of the USB quorum cable indicates that the first node has reserved the USB quorum cable.