International Business Machines Corporation

Stephen J Tovcimak

Lance Warren Russell

Eric Philip Fried

Perinkulam I Ganesh

Rajeev Kumar Mishra

Madhusudanan Kandasamy

Esdras E Cruz-Aguilar

Charles E Meyer

Chris Alan Schwendiman

Stephen M Tee

Murali Vaddagiri

Shevaun M Fontenot

Mechanisms are provided, in a data processing system comprising a plurality of nodes, each node being a computing device, for controlling access to a critical section of code. These mechanisms send, by a sender node of the data processing system, an access request for requesting access to the critical section of code. The critical section of code is a portion of code that accesses a shared resource. The mechanisms receive, in the sender node, from a plurality of receiver nodes in the data processing system, responses to the access request. Each response in the responses includes a number of active nodes perceived by a corresponding receiver node that transmitted the response. The mechanisms control, by the sender node, access to the critical section of code based on the number of active nodes identified in each of the responses received from the receiver nodes.

Enhanced mechanisms for granting access to shared resources

A unique device name is assigned to each of a plurality of shared storage devices in a cluster configuration database defining membership of nodes in a cluster. A particular node among the nodes defined by the cluster configuration database as a member of the cluster searches the cluster configuration database for a device identifier matching a device identifier of a shared storage device hosted by the particular node. In response to finding a matching device identifier in the cluster configuration database, the particular node renames, in a local configuration maintained at the particular node, a storage device associated with the matching device identifier with the unique name assigned to that storage device in the cluster configuration database.

Propagation of unique device names in a cluster system

A second node receives a message from a first node in a cluster environment. The message includes a unique identifier of a shared data storage device including a cluster configuration database that defines membership of nodes in a cluster. In response to receiving the message, the second node attempts to find the shared data storage device. In response to finding the shared data storage device, the second node locates and reads the cluster configuration database on the shared data storage device. The second node then assimilates a cluster configuration update indicated by the cluster configuration database.

Notification of configuration updates in a cluster system

Growing community of inventors

Red Hook, NY, United States of America

Stephen J Tovcimak