Techniques to manage non-disruptive SAN availability in a partitioned cluster

Patent metadata

Field	Value
Publication number	US-9639437-B2
Application number	US-201414526975-A
Country	US
Kind code	B2
Filing date	Oct 29, 2014
Priority date	Dec 13, 2013
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

Techniques to managing non-disruptive SAN availability in a partitioned cluster comprising one or more components configured to determine whether to separate a cluster into two or more partitions, notify one or more responsive cluster nodes to separate the cluster into a first partition and a second partition, update one or more access states, notify the host that access states of one or more network paths has been updated, and provide the one or more access states. Other embodiments are described and claimed.

First claim

The invention claimed is:

1. A method, comprising:
providing, by an electronic device, access states for at least two logical interfaces to a host, the at least two logical interfaces comprising a first and a second logical interfaces, each logical interface being configured to provide access to a first and a second storage units;
receiving, by the electronic device, status information indicating a partition event has occurred;
transitioning, by the electronic device, to a majority partition after the partition event;
disassociating, by the electronic device, from an out of partition cluster node that transitioned to a minority partition after the partition event;
updating, by the electronic device, at least one access state for at least one logical interface;
notifying, by the electronic device, the host of the at least updated access state; and
providing, by the electronic device, the at least one updated access state for the at least one logical interface, such that the host maintains access to the first storage unit via the first logical interface and the second storage unit via the second logical interface after the partition event.

2. The method of claim 1 , further comprising:
determining, by the electronic device, when the partition event has occurred based at least partially on connectivity with a cluster node; and
notifying, by the electronic device, at least one cluster node with status information for the out of partition cluster node.

3. The method of claim 2 , wherein the step of determining further comprises:
sending,by the electronic device, at least one heartbeat signal to the cluster node;
determining, by the electronic device, occurrence of the partition event in the cluster based at least partially on a threshold number of heartbeat response signals received from the cluster node; and
declaring, by the electronic device, the cluster node as the out of partition cluster node after the cluster node fails to respond to the threshold number of heartbeat signals.

4. The method of claim 2 , wherein the status information comprises quorum state information indicating the out of partition cluster node as out-of-quorum and connectivity state information indicating that the out of partition cluster node is out of partition.

5. The method of claim 1 , wherein the disassociating further comprises:
evicting, by the electronic device, at least one component of the out of partition cluster node that transitioned to the minority partition from at least one distributed group; and
leaving, by the electronic device, at least one distributed group managing at least one storage unit of the out of partition cluster node that transitioned to the minority partition.

6. The method of claim 1 , wherein the host is communicatively coupled to the at least two logical interfaces to access the first and second storage units managed by at least two cluster nodes in a cluster, and the partition event separates the cluster into at least two partitions comprising at least the majority partition and the minority partition.

7. The method of claim 1 , wherein the at least one access state indicates that at least one storage unit managed by the out of partition cluster node in the minority partition is inaccessible via the at least one logical interface.

8. An electronic device comprising:
a memory containing machine readable medium comprising machine executable code having stored thereon instructions for performing a method of managing non-disruptive storage area network availability in a partitioned cluster;
a processor coupled to the memory, the processor configured to execute the machine executable code to cause the processor to:
provide access states for at least two logical interfaces to a host, the at least two logical interfaces comprising a first and a second logical interfaces, each logical interface being configured to provide access to a first and a second storage units,
transition to a majority partition or a minority partition after a partition event,
disassociate from an out of partition cluster node that transitioned to a different partition after the partition event,
update at least one access state for at least one logical interface,
notify the host of the at least one updated access state, and
provide the at least one updated access state for the at least one logical interface, such that the host maintains access to the first storage unit via the first logical interface and the second storage unit via the second logical interface after the partition event.

9. The device of claim 8 , wherein the at least one component is to further determine whether the partition event has occurred,
notify at least one cluster node with status information of an out of partition cluster node, and
receive status information indicating a partition event has occurred.

10. The device of claim 9 , wherein the at least one component determines whether the partition event has occurred is to further
send at least one heartbeat signal to a cluster node,
determine occurrence of the partition event based at least partially on a threshold number of heartbeat response signals received from the cluster node, and
declare the cluster node as the out of partition cluster node after the cluster node fails to respond to the threshold number of heartbeat signals.

11. The device of claim 9 , wherein the status information comprises quorum state information indicating the out of partition cluster node that transitioned to a different partition as out-of-quorum and connectivity state information indicating that the out of partition cluster node as out of partition.

12. The device of claim 8 , wherein the at least component is to further
evict at least one component of the out of partition cluster node that transitioned to the different partition from at least one distributed group, and
leave at least one distributed group managing at least one storage unit of the out of partition cluster node that transitioned to the different partition.

13. The device of claim 8 , wherein the host is communicatively coupled to the at least two logical interfaces to access the first and second storage units managed by at least two cluster nodes in a cluster, and the partition event separates the cluster into at least two partitions comprising at least the majority partition and the minority partition.

14. The device of claim 8 , wherein the at least one access state indicates that at least one storage unit managed by the out of partition cluster node in the different partition is inaccessible via the at least one logical interface.

15. A non-transitory machine readable medium having stored thereon instructions for performing a method comprising machine executable code which when executed by at least one machine, cause the machine to:
provide access states for at least two logical interfaces to a host, the at least two logical interfaces comprising a first and a second logical interfaces, each logical interface being configured to provide access to a first and a second storage units;
transition to a minority partition after a partition event;
disassociate from an out of partition cluster node that transitioned to a majority partition after the partition event;
update at least one access state for at least one logical interface;
notify the host of the at least updated access state; and
provide the at least one updated access state for the at least one logical interface, such that the host maintains access to the first storage unit via the first logical interface and the second storage unit via the second logical interface after th

Assignees

• Netapp Inc

Inventors

• Hildebrand John
• Brown Geoffrey Stewart
• Baker Nathan
• Meneghini John
• Knight Frederick
• Rao Santosh

Classifications

• G06F11/2089

  Redundant storage control functionality · CPC title

• G06F11/2094

  Redundant storage or storage space (G06F11/2056 takes precedence) · CPC title

• G06F3/0644 Primary

  Management of space entities, e.g. partitions, extents, pools · CPC title

• G06F11/201 Primary

  between storage system components · CPC title

• G06F11/1425

  by reconfiguration of node membership · CPC title