| Patent application number | Description | Published |
|---|
| 20080282244 | Distributed transactional deadlock detection - Aspects of the subject matter described herein relate to deadlock detection in distributed environments. In aspects, nodes that are part of the environment each independently create a local wait-for graph. Each node transforms its local wait-for graph to remove non-global transactions that do not need resources from multiple nodes. Each node then sends its transformed local wait-for graph to a global deadlock monitor. The global deadlock monitor combines the local wait-for graphs into a global wait-for graph. Phantom deadlocks are detected and removed from the global wait-for graph. The global deadlock monitor may then detect and resolve deadlocks that involve global transactions. | 11-13-2008 |
| 20100082546 | Storage Tiers for Database Server System - A technique is described for storing data from a database across a plurality of data storage devices, wherein each data storage device is capable of being accessed only by a corresponding computer system in a group of interconnected computer systems. In accordance with the technique, an identifier of the database is received. An identifier of a storage tier instance is also received, wherein the storage tier instance comprises a logical representation of one or more storage locations within each of the data storage devices. Responsive to the receipt of the identifier of the database and the identifier of the storage tier instance, data from the database is stored in two or more of the storage locations logically represented by the storage tier instance, wherein each of the two or more storage locations in which data is stored is within a corresponding one of the data storage devices. | 04-01-2010 |
| 20100082551 | DATA PLACEMENT TRANSPARENCY FOR HIGH AVAILABILITY AND LOAD BALANCING - A method of updating a clone data map associated with a plurality of nodes of a computer system is disclosed. The clone data map includes node identification data and clone location data. A node failure event of a failed node of the computer system that supports a primary clone is detected. The clone data map is updated such that a secondary clone stored at a node other than the failed node is marked as a new primary clone. In addition, clone data maps may be used to perform node load balancing by placing a substantially similar number of primary clones on each node of a node cluster or may be used to increase or decrease a number of nodes of the node cluster. Further, data fragments that have a heavy usage or a large fragment size may be reduced in size by performing one or more data fragment split operations. | 04-01-2010 |
| 20100088289 | TRANSITIONING CLONE DATA MAPS AND SYNCHRONIZING WITH A DATA QUERY - Methods, systems, and computer-readable media are disclosed for transitioning clones and clone data access maps in response to node or media failure without blocking queries. In a system, a data request interface is configured to receive a query to access data at a storage device. Data management logic is configured to access clone state information of a plurality of clones including clones in a static state and clones in a transitory state. The data management logic is further configured to process the query to access the data according to the dynamic clone data access map, with functional correctness maintained. | 04-08-2010 |
| 20100185714 | DISTRIBUTED COMMUNICATIONS BETWEEN DATABASE INSTANCES - A database communication system is described herein that structures communications in a way that provides lower overhead tracking, statistics, semantics for closing a communication, and reliability. The system provides communication namespaces that organize communications by component, purpose, and instance, which allow database servers to implicitly create communication-related objects without central coordination. The database communication system enables group-based communications that streamline the development of complex distributed components and protocols by providing creation and management of communications namespaces, centralized cleanup support, and centralized monitoring. These features allow the system to be highly distributed, with no one single coordinator of operations, and still provide reliable communications. Thus, the system allows databases to be spread across multiple servers while keeping the burden on database server developers of managing communications between the servers low. | 07-22-2010 |
