Abstract: A system, method and computer program product for synchronizing replicas of shared data structures associated with one or more computer systems. The method comprises: evaluating a metric for performing a replica synchronization operation on a first computer system according to a first synchronization method; evaluating the metric for performing a replica synchronization operation on the first computer system according to a second synchronization method; and, selecting, at synchronization time, based on the evaluated metric, whether to use the first or second synchronization methods, and communicating a command to a second computer system to replicate a shared data structure based on the selected synchronization method.

Abstract: A method, system and computer program product for compressing state changes to a datum in a primary data storage system. One embodiment of the invention involves receiving a first state-change entry describing at least a first transformation of the datum and an first value of the datum and receiving a second state-change entry describing at least a second transformation of the datum an a second value of the datum. The first and second state-change entries are reduced to a compressed state-change entry including a compressed transformation and a compressed value that are functionally equivalent applying the first transformation and first value, then applying the second transformation and second value, to the datum. The techniques of the invention may be utilized, for example, in redo and undo database replication operations.

Abstract: Techniques for constructing a software application are provided. A data model of the application is represented as a relational model. Control logic of the application is defined as a mapping from a current state of the application data model and one or more application inputs to a new state of the application data model and one or more application outputs, described by relational algebra components.

Abstract: A finger for a crop gathering auger of a grain header for an agricultural combine, including a tether which spans a failure region of the finger and will retain a free end of the finger in connection with a mounting end thereof when the failure region is broken, and which is preferably additionally operable for automatically retracting the broken off free end into an auger drum and retaining it therein during subsequent rotation of the drum for limiting potential damage from the broken end and preventing entry of the broken end into crop handling equipment of the combine.

Abstract: Ground sensing apparatus for a header of an agricultural harvesting machine, configurable for sensing the ground with a cutter bar of the header in a fixed and/or raised position. The apparatus utilizes a linkage arrangement in connection with a sensor shaft and a skid shoe deployable to a lowered position and movable when in the lowered position for effecting rotations of the sensor shaft and thus signaling to an appropriate control, information relating to contact with the ground.

Abstract: One embodiment of the present method and apparatus for synchronization of client transactions executed by an autonomous client enables a client operating on a limited connection to a server to log transactions executed against a locally stored server database state. Logged transactions are then synchronized with a current server database state by delivering the transaction log to the server, which re-executes each logged client transaction against the current server database state, thereby reducing synchronization-related transaction conflicts.

Abstract: A server allocation controller provides an improved distributed data processing system for facilitating dynamic allocation of computing resources. The server allocation controller supports transaction and parallel services across multiple data centers enabling dynamic allocation of computing resources based on the current workload and service level agreements. The server allocation controller provides a method for dynamic re-partitioning of the workload to handle workload surges. Computing resources are dynamically assigned among transaction and parallel application classes, based on the current and predicted workload. Based on a service level agreement, the server allocation controller monitors and predicts the load on the system. If the current or predicted load cannot be handled with the current system configuration the server allocation controller determines additional resources needed to handle the current or predicted workload. The server cluster is reconfigured to meet the service level agreement.

Abstract: An on-demand manager provides an improved distributed data processing system for facilitating dynamic allocation of computing resources among multiple domains based on a current workload and service level agreements. Based on a service level agreement, the on-demand manager monitors and predicts the load on the system. If the current or predicted load cannot be handled with the current system configuration, the on-demand manager determines additional resources needed to handle the workload. If the service level agreement violations cannot be handled by reconfiguring resources at a domain, the on-demand manager sends a resource request to other domains. These other domains analyze their own commitments and may accept the resource request, reject the request, or counter-propose with an offer of resources and a corresponding service level agreement.

Abstract: A multi-nodal data processing system includes a plurality of processing nodes, each node connected to plural other nodes by bidirectional data links. Each node comprises receivers for receiving messages on bidirectional data links and transmitters for transmitting messages on bidirectional data links. Each node records child nodes to which a message was transmitted and is further adapted to transmit a lock-up message received from a child node to a parent node, the lock-up message indicating a successful establishment of a message signal path to a destination node. Each node further is adapted to transmit a link cancel signal to another node to close the link in the event of an unsuccessful message transfer attempt over the link. Each node inhibits transmission of a lock-up signal to a parent node until link cancel signals have been received from all child nodes (other than a node from which a lock-up signal was received).

Abstract: A test link protocol which continuously monitors each link in a network to ensure that the link is correctly transmitting data. Each switch, or torus has at least one of two functional components: Send Test and Receive Test. The Send Test component monitors control codes at a torus link output. The Receive Test component monitors control codes at a torus link input. After a predetermined interval, the Send Test component makes a request to send a test.sub.-- link control code. The torus sends the test.sub.-- link code to the neighboring torus, where it is removed from the data stream and sent to that torus' Receive Test. The Receive Test then generates a response message and makes a request to send that message back to the originating torus. After receiving the message, the Send Test analyzes the message to determine whether the network link is working correctly. An error is also declared if the Send Test does not receive a reply within a predetermined interval.