US 7139925

Patent Overview — US 7,139,925 B2

Title: System and method for dynamic cluster adjustment to node failures in a distributed data system

Patent number / application: US 7,139,925 B2; Application US 10/134,782

Inventors: Darpan Dinker, Mahesh Kannan, Pramod Gopinath

Original assignee: Sun Microsystems, Inc. Current assignee listed: Oracle America, Inc.

Dates: Priority/filing date 2002-04-29; publication of US 2003/0204786 A1 on 2003-10-30; granted 2006-11-21. Status listed as "Expired – Lifetime," with adjusted expiration 2023-11-09.

Purpose: The patent addresses managing dynamic cluster membership in distributed data systems. Data may be distributed across nodes forming a cluster; clustering may enable load balancing, high availability, and scalability, and redundant data may be maintained by replication. The excerpt states the invention manages cluster membership and data separately, for example via an event notification mechanism between management layers, with a topology manager and a state manager interacting through a defined interface. The topology manager ensures the dynamic cluster forms a topologically specified arrangement, and may use finite state automata defining node functions, operating states, communication, and state transitions (five membership states and five messages are mentioned).

Plain-language scope (per the excerpt): Cluster members are configured to form a ring topology. A static topology indicates node ordering; under normal operation the cluster topology may match it, and otherwise the cluster topology may be a ring approaching the static topology as current membership requires. Nodes may have access to static topology information. On a node failure, neighboring nodes (the failed node's previous and next nodes) detect the death, update local topology data, send node dead messages, and reconnect—e.g., a connecting node sends a connect request, the other sends a node joined message, and a connect complete message follows—so remaining nodes function as cluster members.

Source: https://patents.google.com/patent/US7139925/en

What the excerpt does not establish: It provides no claims, no named prior-art references, no claim-by-claim scope, no legal conclusions on validity or enforceability, and no details on litigation or ownership transfers beyond the listed assignment records.