Clustered filesystem with membership version support

• US 8,683,021 B2
• Filed: 08/16/2011
• Issued: 03/25/2014
• Est. Priority Date: 06/05/2001
• Status: Expired due to Fees

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Silicon Graphics International Corporation (Hewlett-Packard Enterprise Company)
• Inventors: Beck, Kenneth S.
• Primary Examiner(s): Beausoliel, Jr., Robert
• Assistant Examiner(s): Rayyan, Susan F
• Application Number:
  US13/211,200
• Publication Number:
  US 20120072558A1
• Time in Patent Office: 952 Days
• Field of Search: None
• US Class Current: 709/221
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• 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]
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/566 Grouping or aggregating service requests, e.g. for unified processing
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/966 Distributed

Abstract

A computer system with read/write access to storage devices creates a snapshot of a data volume at a point in time while continuing to accept access requests to the mirrored data volume by copying before making changes to the base data volume. Multiple snapshots may be made of the same data volume at different points in time. Only data that is not stored in a previous snapshot volume or in the base data volume are stored in the most recent snapshot volume.

Claims

1. A method for establishing a new cluster membership of computer system nodes sharing direct read/write access to storage devices via a storage area network and a cluster operating system, the method comprising:

initiating operation of a node;

transitioning the node into a nascent state;

detecting by the node heartbeat signals from other nodes;

transmitting by the node its heartbeat signal;

determining that a sufficient number of heartbeat signals have been detected sufficient to form a viable cluster;

determining that an established cluster exists in response to detecting sufficient nodes to form a viable cluster;

receiving at the node a request for information from a node in a leader state;

transitioning the node to a follower state in response to the request;

transmitting by the node identification information in response to the request to the node in the leader state;

receiving at the node a membership proposal and information pertaining to all nodes in the proposed membership from the node in the leader state;

accepting membership by the node in the proposed membership in the cluster;

transitioning the node to a stable state; and

forming a viable cluster including all nodes in the membership proposal.

2. The method of claim 1, further comprising:

transitioning the node to a dead state in response to an insufficient number of nodes to form a cluster.

3. The method of claim 1, further comprising:

transitioning the node to the follower state for cluster membership reestablishment in response to a node in the cluster changing to the leader state.

4. The method of claim 3, further comprising:

transitioning the node to the stable state upon reestablishing the cluster membership.

5. The method of claim 1, further comprising:

requesting by the node withdrawal from the cluster membership;

receiving by the node an acknowledgment from the node in the leader state; and

transitioning the node to a shutdown state.

6. The method of claim 1, further comprising:

transitioning the node to the follower state in response to a number of nodes falling below a level sufficient for a viable cluster.

7. The method of claim 6, further comprising:

transitioning the node to a dead state upon failure to establish a viable cluster.

8. A system for establishing a new cluster membership of computer system nodes sharing direct read/write access to storage devices via a storage area network and a cluster operating system, comprising:

a processor;

a memory;

one or more software modules that are stored in memory and executed by the processor to;

initiate the operation of a node;

transition the node into a nascent state;

detect heartbeat signals from other nodes;

transmit a heartbeat signal from the node;

determine whether a sufficient number of heartbeat signals have been detected is sufficient to form a viable cluster;

determine whether an established cluster exists in response to detecting sufficient nodes to form a viable cluster;

receipt at the node a request for information from a node in a leader state;

transition the node to a follower state in response to the request;

transmit identification information in response to the request for information to the node in the leader state;

receipt at the node a membership proposal and information pertaining to all nodes in the proposed membership from a node in the leader state;

accept membership by the node in the proposed membership in the cluster;

transition the node to a stable state; and

form a viable cluster including all nodes in the membership proposal.

9. The system of claim 8, wherein the one or more software modules are executable by the processor to transition the node to a dead state in response to an insufficient number of nodes to form a cluster.

10. The system of claim 8, wherein the one or more software modules are executable by the processor to transition the node to the follower state for cluster membership reestablishment in response to a node in the cluster changing to the leader state.

11. The system of claim 10, wherein the one or more software modules are executable by the processor to transition the node to the stable state upon reestablishing the cluster membership.

12. The system of claim 8, wherein the one or more software modules are executable by the processor to request withdrawal from the cluster membership, wherein the one or more software modules are executable by the processor to transition receive an acknowledgment from the node in the leader state, and wherein the one or more software modules are executable by the processor to transition the node to a shutdown state.

13. The system of claim 8, wherein the one or more software modules are executable by the processor to transition the node to the follower state in response to a number of nodes falling below a level sufficient for a viable cluster.

14. The system of claim 13, wherein the one or more software modules are executable by the processor to transition the node to a dead state upon failure to establish a viable cluster.

15. A non-transitory computer readable storage medium having embodied thereon a program executable by a processor to perform a method for establishing a new cluster membership of computer system nodes sharing direct read/write access to storage devices via a storage area network and a cluster operating system, the method comprising:

initiating operation of a node;

transitioning the node into a nascent state;

detecting by the node heartbeat signals from other nodes;

transmitting a heartbeat signal by the node;

determining whether a sufficient number of heartbeat signals have been detected sufficient to form a viable cluster;

determining whether an established cluster exists in response to detecting sufficient nodes to form a viable cluster;

receiving at the node a request for information from a node in a leader state;

transitioning the node to a follower state in response to the request;

transmitting by the node identification information in response to the request to the node in the leader state;

receiving at the node a membership proposal and information pertaining to all nodes in the proposed membership from a node in the leader state;

accepting membership by the node in the proposed membership in the cluster;

transitioning the node to a stable state; and

forming a viable cluster including all nodes in the membership proposal.

16. The non-transitory computer readable storage medium of claim 15, wherein the method includes transitioning the node to a dead state in response to an insufficient number of nodes to form a cluster.

17. The non-transitory computer readable storage medium of claim 15, wherein the method includes transitioning the node to the follower state for cluster membership reestablishment in response to a node in the cluster changing to the leader state.

18. The non-transitory computer readable storage medium of claim 17, wherein the method includes transitioning the node to the stable state upon reestablishing the cluster membership.

19. The non-transitory computer readable storage medium of claim 15, wherein the method includes requesting withdrawal from the cluster membership, wherein the method includes receiving an acknowledgment from the node in the leader state, and wherein the method includes transitioning the node to a shutdown state.

20. The non-transitory computer readable storage medium of claim 15, wherein the method includes transitioning the node to the follower state in response to a number of nodes falling below a level sufficient for a viable cluster and transitioning the node to a dead state upon failure to establish a viable cluster.