Data processing lock signal transmission

Patent metadata

Field	Value
Publication number	US-10833979-B2
Application number	US-201916440620-A
Country	US
Kind code	B2
Filing date	Jun 13, 2019
Priority date	Feb 22, 2013
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

In accordance with one aspect of the present description, a node of the distributed computing system has multiple communication paths to a data processing resource lock which controls access to shared resources, for example. In this manner, at least one redundant communication path is provided between a node and a data processing resource lock to facilitate reliable transmission of data processing resource lock signals between the node and the data processing resource lock. Other features and aspects may be realized, depending upon the particular application.

First claim

What is claimed is:

1. A computer implemented method, comprising:
under control of a first server node of a distributed computer storage system,
transmitting over a first communication path to a failover lock device, a first request to be granted a failover lock of the failover lock device; and
transmitting over a second communication path to the failover lock device, a second request to be granted the failover lock of the failover lock device.

2. The computer implemented method of claim 1 wherein the first server node is a first data processing unit, the method further comprising:
under control of the first data processing unit,
prior to determining that a communication failure has occurred over the first communication path in connection with the transmission of the first request; transmitting by said first data processing unit over the second communication path to the failover lock device, the second request to be granted the failover lock; and
determining whether the failover lock was obtained by the first data processing unit in response to either of said transmissions of the first and second requests to be granted the failover lock.

3. The method of claim 2 further comprising determining whether communication failures occurred over both said first and second communication paths including initiating a timeout period to wait for a grant of a requested failover lock, and determining whether the timeout period has expired prior to receiving a grant of either of the first and second requests to be granted a failover lock.

4. The method of claim 3 wherein the determining whether the failover lock was obtained includes determining prior to expiration of the timeout period, whether the failover lock was obtained by the first data processing unit in response to either of said transmissions of the first and second requests to be granted the failover lock.

5. The method of claim 2 wherein the failover lock includes a data unit lock which controls access to a shared unit of data.

6. The method of claim 2 wherein the failover lock includes a data processing resource lock which controls access to a shared hardware resource.

7. The method of claim 2 further comprising determining that the failover lock was obtained by the first data processing unit in response to either of said transmissions of the first and second requests to be granted the failover lock, and performing by the first data processing unit a failover which includes accessing shared data processing resources using the failover lock held by the first data processing unit.

8. The method of claim 2 further comprising:
under control of the first data processing unit,
transmitting by the first data processing unit over the first communication path to the failover lock device, a first release of a failover lock granted to the first data processing unit;
prior to determining that a communication failure has occurred over the first communication path in connection with the transmission of the first release, transmitting by said first data processing unit over the second communication path, a second release of the failover lock granted to first data processing unit; and
determining whether the failover lock was released by the first data processing unit in response to either of said transmissions of the first and second releases of the failover lock; and
determining whether communication failures occurred over both said first and second communication paths in connection with said transmissions of the first and second releases, respectively.

9. The method of claim 1 further comprising receiving by said server node a grant of a request to be granted the failover lock of the failover lock device, and, performing by the server node a failover which includes accessing shared hardware resources associated with the failover lock using the failover lock held by the server node.

10. A computer program product for a distributed computing system having a plurality of processor nodes including a first data processing unit, the computer program product comprising a non-transitory computer readable storage medium having computer readable program code embodied therein for execution by a processor of the first data processing unit to perform operations, the operations comprising:
under control of the first data processing unit,
transmitting by the first data processing unit over a first communication path to a failover lock device, a first request to be granted a failover lock, and
transmitting by said first data processing unit over a second communication path to the failover lock device, a second request to be granted the failover lock.

11. The computer program product of claim 10 wherein the operations further comprise determining whether communication failures occurred over both said first and second communication paths including initiating a timeout period to wait for a grant of a requested failover lock, determining whether the timeout period has expired prior to receiving a grant of either of the first and second requests to be granted a failover lock, and determining whether the failover lock was obtained including determining prior to expiration of the timeout period, whether the failover lock was obtained by the first data processing unit in response to either of said transmissions of the first and second requests to be granted the failover lock.

12. The computer program product of claim 10 wherein the failover lock is one of a data unit lock which controls access to a shared unit of data, and a data processing resource lock which controls access to a shared hardware resource.

13. The computer program product of claim 10 wherein the operations further comprise determining that the failover lock was obtained by the first data processing unit in response to either of said transmissions of the first and second requests to be granted the failover lock, and performing by the first data processing unit a failover which includes accessing shared data processing resources using the failover lock held by the first data processing unit.

14. The computer program product of claim 10 wherein the operations further comprise:
under control of the first data processing unit,
transmitting by the first data processing unit over the first communication path to the failover lock device, a first release of a failover lock granted to the first data processing unit;
prior to determining that a communication failure has occurred over the first communication path in connection with the transmission of the first release, transmitting by said first data processing unit over the second communication path, a second release the failover lock granted to first data processing unit; and
determining whether the failover lock was released by the first data processing unit in response to either of said transmissions of the first and second releases of the failover lock; and
determining whether communication failures occurred over both said first and second communication paths in connection with said transmissions of the first and second releases, respectively.

15. A distributed computing storage controller system for use with a plurality of hosts and a plurality of storage devices, comprising:
a plurality of processor nodes including a first data processing unit having a processor, said processor nodes for transferring data between the plurality of hosts and the plurality of storage devices;
a memory having a plurality of units of shared data;
a plurality of shared resources;
a failover lock device providing a failover lock for controlling access by said plurality of nodes to at

Assignees

• IBM

Inventors

• Colpo Yolanda
• Elliott John C
• Garcia Enrique Q
• Juarez Larry
• Sorenson Todd C

Classifications

• H04L45/22 Primary

  Alternate routing · CPC title

• G06F9/526 Primary

  Mutual exclusion algorithms · CPC title

• G06F11/0757

  by exceeding a time limit, i.e. time-out, e.g. watchdogs · CPC title

• G06F11/221

  to test buses, lines or interfaces, e.g. stuck-at or open line faults · CPC title

• G06F21/70

  Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer · CPC title