International Business Machines Corporation

Ambuj Goyal

Daniel Manuel Dias

Francis Nicholas Parr

Anupam K Bhide

Manoj N Kumar

Joel Leonard Wolf

George Prentice Copeland

Chandrasekaran Mohan

David Yu Chang

Asit Dan

Hui-I Hsiao

Anant Deep Jhingran

Marc Gregory Smith

Bharat D Rathi

Werner K Bux

A certain number of agents and tokens are created. A first agent that is assigned a request must obtain a token to process the request. The number of agents which may concurrently process requests are limited by preventing an agent from processing a request unless the agent has an assigned token. An additional agent is created after assigning the token to the first agent, provided that an existing agent is not available to wait for a request, and an unassigned token is available for the additional agent. A certain minimum number of agents is defined and an agent is automatically eliminated when the agent completes a request, provided that the number of agents that are assigned tokens exceeds the minimum number of agents.

System for allocating resources among agent processes

A conversation monitoring system includes a communication network, two or more parties coupled to the communication network, each party having a computer application, and a conversation monitor located at at least one of the parties and adapted to provide an interaction history of long running conversations accessible to each computer application.

Interaction monitor and interaction history for service applications

A method and system are provided for partitioning a database and for balancing the processing load among processing nodes in a data processing system. A database partition is stored at each node and a logical owner node is assigned to each partition. The logical owner becomes responsible for all database requests related to the corresponding partition. Techniques for optimally assigning logical owners to all partitions in a system are provided and are responsive to parameters such as the load at each node, the combined load of the system, and the total number of assignments allowed. Techniques are also provided to accomplish the transfer of partition ownership between processing nodes when multiple transactions related to the partition are simultaneously occurring.

Method and system for database load balancing

In a partitioned database system of the Shared Nothing type, one or more secondary replicas of each partition are maintained by spooling (i.e., asynchronously sending) modified (usually called dirty) pages from the primary replica to the secondary replica(s) rather than by using a synchronous page update or by sending log entries instead of entire pages. A Write-Ahead Log protocol is used so that a dirty page is not forced to non-volatile storage until a log record of the modification is created and written to non-volatile storage. Replica updating does not delay the committing of transactions because replica updating is done asynchronously with respect to transaction processing. Since dirty pages are sent rather than only log entries, disk accesses and processing at the secondary replica(s) arising from the maintaining of the replicas are minimized as well. Only one centrally accessible log is maintained for all replicas of the same partition.

Asynchronous replica management in shared nothing architectures

An apparatus, embodied in an Intelligent Page Store, for providing concurrent and consistent access to a functionally separate transaction entity and a query entity to a shared database, while maintaining a single physical copy of most of the data. The Intelligent Page Store contains shared disk storage, and an intelligent versioning mechanism allows simultaneous access by the transaction entity and the query entity to the shared data. The transaction entity is presented the current data and the query entity is presented a recent and consistent version of the data. A single copy of all but recently updated pages is maintained by the Intelligent Page Store. The query and transaction entities operate independently of each other and are separately optimized.

Intelligent page store for concurrent and consistent access to a

A computer system processes mixed control, indexing and data manipulation instructions in groups of N instructions at a time. A group of instructions is applied to a set of N Dispatch units which execute the control and indexing instructions directly. The Dispatch Units convert data manipulation instructions into a more primitive data flow operations. The data flow operations are applied to a set of M Execution Units which process the operations concurrently by observing data dependency constraints. The data used by the control and indexing instructions is stored in a group of identical memory structures which are accessible by each of the Dispatch Units. Data for the data manipulation instructions is stored in a data structure which is divided among the Execution Units.

Computer architecture for the concurrent execution of sequential programs

A method and apparatus used to detect errors in a signal transmitted over a single wire. All transient errors are detected when the effect of the transient lasts for at least one cycle and not more than five cycles. Transient errors of longer duration will be detected if the level of the original signal at the start of the transient is different from that at the end of the transient. Stuck faults will be deleted if one onset of the stuck fault causes the level of the signal to change. Redundancy is incorporated by introducing redundant transitions in the signal on the same wire. This requires the successive transitions in the original signal to be at least three cycles apart. If a transition is viewed as a binary one and the absence of a transition as a binary zero then each binary one is replaced with the sequence 'one-one-one' (overwriting subsequent zeros), and keeping each zero as the single bit 'zero'. Upon decoding, each group of three transitions is converted to a single transition. Signals having more than or less than three consecutive transitions which are not in multiples of three are determined to be in error.

Method and apparatus for detecting transient errors

In a communication system comprising several stations, access to the ring is granted to one station at a time by circulating a token on the ring and updating the priority of the token is disclosed. This invention provides for a first station to transmit a token immediately after it has finished transmitting a frame containing a packet(s) needed to be transmitted from the first station without waiting for the header of the frame to return to the first station. A priority signalling packet is then transmitted on the ring from the first station after the first station transmits the token on the ring. This priority signalling packet contains information as to the particular priority level that the token should be updated to. Finally, the priority level of the token is updated to correspond to the particular priority level when the priority signalling packet reaches the station that holds the token.

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Amawalk, NY, United States of America

Ambuj Goyal