Abstract: A method and system for achieving time-awareness in the highly available, fault-tolerant execution of components in a distributed computing system, without requiring the writer of these components to explicitly write code (such as entity beans or database transactions) to make component state persistent. It is achieved by converting the intrinsically non-deterministic behavior of the distributed system to a deterministic behavior, thus enabling state recovery to be achieved by advantageously efficient checkpoint-replay techniques. The system is deterministic by repeating the execution of the receiving component by processing the messages in the same order as their associated timestamps and time-aware by allowing adjustment of message execution based on time.

Abstract: A method comprises estimating a performance of a processing system using queueing theory wherein the processing system comprises a network that accepts at least one input message stream from a plurality of publishing clients, transforms the at least one input message stream into at least one output message stream utilizing the plurality of transforms distributed in a first assignment among the plurality of brokers, and delivers the at least one output message stream to at least one of the plurality of subscribing clients, performing optimization upon the assignment of the plurality of transforms using the estimated performance to produce a second assignment, and reassigning the plurality of transforms in accordance with the second assignment.

Abstract: A method and system for achieving time-awareness in the highly available, fault-tolerant execution of components in a distributed computing system, without requiring the writer of these components to explicitly write code (such as entity beans or database transactions) to make component state persistent. It is achieved by converting the intrinsically non-deterministic behavior of the distributed system to a deterministic behavior, thus enabling state recovery to be achieved by advantageously efficient checkpoint-replay techniques. The system is deterministic by repeating the execution of the receiving component by processing the messages in the same order as their associated timestamps and time-aware by allowing adjustment of message execution based on time.

Abstract: Computer implemented method, system and computer usable program code for achieving transactional quality of service in a transactional object store system. A transaction is received from a client and is executed, wherein the transaction comprises reading a read-only derived object, or reading or writing another object, and ends with a decision to request committing the transaction or a decision to request aborting the transaction. Responsive to a decision to request committing the transaction, wherein the transaction comprises writing a publishing object, events are delivered to event stream processing queries, and are executed in parallel with executing of the transaction.

Abstract: Method, system and computer readable program code for dynamic and evolutionary component placement in an event processing system having producers, consumers, a plurality of nodes between the producers and the consumers, and a flow graph representing operator components to be executed between the producers and the consumers. A description of a change to the system is received. At each node, next-hop neighbor nodes for each consumer are identified. A routing value is assigned to each next-hop neighbor node for each consumer and the routing values are updated according to an update rule that represents a chromosome in a routing probe. The update rule in a routing probe is selectively updated from a plurality of update rules at the consumer. The probability of selecting a particular update rule is reinforced or decayed based on the success of an update rule in allowing routing probes to create many different efficient routes.

Abstract: A method and system for achieving highly available, fault-tolerant execution of components in a distributed computing system, without requiring the writer of these components to explicitly write code (such as entity beans or database transactions) to make component state persistent. It is achieved by converting the intrinsically non-deterministic behavior of the distributed system to a deterministic behavior, thus enabling state recovery to be achieved by advantageously efficient checkpoint-replay techniques. The method comprises: adapting the execution environment for enabling message communication amongst and between the components; automatically associating a deterministic timestamp in conjunction with a message to be communicated from a sender component to a receiver component during program execution, the timestamp representative of estimated time of arrival of the message at a receiver component.

Abstract: Method, system and computer readable program code for dynamic and evolutionary component placement in an event processing system having producers, consumers, a plurality of nodes between the producers and the consumers, and a flow graph representing operator components to be executed between the producers and the consumers. A description of a change to the system is received. At each node, next-hop neighbor nodes for each consumer are identified. A routing value is assigned to each next-hop neighbor node for each consumer and the routing values are updated according to an update rule that represents a chromosome in a routing probe. The update rule in a routing probe is selectively updated from a plurality of update rules at the consumer. The probability of selecting a particular update rule is reinforced or decayed based on the success of an update rule in allowing routing probes to create many different efficient routes.

Abstract: A method and system for achieving time-awareness in the highly available, fault-tolerant execution of components in a distributed computing system, without requiring the writer of these components to explicitly write code (such as entity beans or database transactions) to make component state persistent. It is achieved by converting the intrinsically non-deterministic behavior of the distributed system to a deterministic behavior, thus enabling state recovery to be achieved by advantageously efficient checkpoint-replay techniques. The system is deterministic by repeating the execution of the receiving component by processing the messages in the same order as their associated timestamps and time-aware by allowing adjustment of message execution based on time.

Abstract: A method comprises estimating a performance of a processing system using queuing theory wherein the processing system comprises a network that accepts at least one input message stream from a plurality of publishing clients, transforms the at least one input message stream into at least one output message stream utilizing the plurality of transforms distributed in a first assignment among the plurality of brokers, and delivers the at least one output message stream to at least one of the plurality of subscribing clients, performing optimization upon the assignment of the plurality of transforms using the estimated performance to produce a second assignment, and reassigning the plurality of transforms in accordance with the second assignment.

Abstract: Systems, methods and computer program products for improving overall end-to-end runtime latency of flow graphs of message transformations which are placed onto an overlay network of broker machines by aggressively replicating stateless transformations.

Abstract: A content-based publish/subscribe system for providing gapless message delivery from a publishing client to a subscribing client is disclosed. The system includes a plurality of brokers operatively coupled to one another via a network. Each of the brokers include at least one processor and are configured as a publisher-hosting broker, a subscriber-hosting broker or an intermediate broker. The subscriber-hosting broker may be operatively coupled to the publisher-hosting broker via the network through the intermediate broker. At least a portion of the plurality of brokers are configured so as to eliminate a need for persistent storage of messages at the intermediate broker and to substantially guarantee a gapless delivery of one or more messages transmitted by the publishing client to the subscribing client, even in the presence of a failure in the publish/subscribe system.

Abstract: A method and system for achieving highly available, fault-tolerant execution of components in a distributed computing system, without requiring the writer of these components to explicitly write code (such as entity beans or database transactions) to make component state persistent. It is achieved by converting the intrinsically non-deterministic behavior of the distributed system to a deterministic behavior, thus enabling state recovery to be achieved by advantageously efficient checkpoint-replay techniques. The method comprises: adapting the execution environment for enabling message communication amongst and between the components; automatically associating a deterministic timestamp in conjunction with a message to be communicated from a sender component to a receiver component during program execution, the timestamp representative of estimated time of arrival of the message at a receiver component.

Abstract: A method comprises estimating a performance of a processing system using queueing theory wherein the processing system comprises a network that accepts at least one input message stream from a plurality of publishing clients, transforms the at least one input message stream into at least one output message stream utilizing the plurality of transforms distributed in a first assignment among the plurality of brokers, and delivers the at least one output message stream to at least one of the plurality of subscribing clients, performing optimization upon the assignment of the plurality of transforms using the estimated performance to produce a second assignment, and reassigning the plurality of transforms in accordance with the second assignment.

Abstract: Systems, methods and computer program products for improving overall end-to-end runtime latency of flow graphs of message transformations which are placed onto an overlay network of broker machines by aggressively replicating stateless transformations.

Abstract: A publish/subscribe system is non-disruptively reconfigured, such that messages are not lost during the reconfiguration. After reconfiguration is initiated, messages that are to be delivered within the publish/subscribe system are forwarded using either an old path or a new path. That is, until the reconfigured system is stabilized, some messages may be delivered using the old path, while other messages are delivered using a new path. After the system is stabilized, the new path is used for delivery of all the messages, until another reconfiguration is initiated.

Abstract: A content-based publish/subscribe system for providing gapless message delivery from a publishing client to a subscribing client, the system includes a plurality of brokers operatively coupled to one another via a network. Each of the brokers include at least one processor and are configured as a publisher-hosting broker, a subscriber-hosting broker or an intermediate broker. The subscriber-hosting broker is operatively coupled to the publisher-hosting broker via the network through the intermediate broker. At least a portion of the plurality of brokers are configured so as to eliminate a need for persistent storage of messages at the intermediate broker and to substantially guarantee a gapless delivery of one or more messages transmitted by the publishing client to the subscribing client, even in the presence of a failure in the publish/subscribe system.

Abstract: A facility is provided for distributing events to consumers in a content-based publish-subscribe system, wherein the consumers each have at least one subscription. The facility includes deriving a set of g approximate multicast groups from a larger set of G possible multicast groups in the publish-subscribe system. The deriving includes exploiting knowledge of subscription predicates of the consumers of the publish-subscribe system. The set of G possible multicast groups is collapsed to the smaller set of g approximate multicast groups, while minimizing the expected performance penalty in using the approximate multicast groups. The set of g approximate multicast groups is then used to forward events to consumers within the publish-subscribe system.

Abstract: A content-based publish/subscribe system for providing gapless message delivery from a publishing client to a subscribing client, the system includes a plurality of brokers operatively coupled to one another via a network. Each of the brokers include at least one processor and are configured as a publisher-hosting broker, a subscriber-hosting broker or an intermediate broker. The subscriber-hosting broker is operatively coupled to the publisher-hosting broker via the network through the intermediate broker. At least a portion of the plurality of brokers are configured so as to eliminate a need for persistent storage of messages at the intermediate broker and to substantially guarantee a gapless delivery of one or more messages transmitted by the publishing client to the subscribing client, even in the presence of a failure in the publish/subscribe system.

Abstract: A technique for optimizing published event message sequences destined for information subscribers in an information processing system. Subscribers specify event interpretation rules which map event message streams into states. The event interpretation rules are maintained elsewhere in the system in preparation for providing optimized, possibly shorter, event message streams to subscribers, sufficient to correctly update the states. If a subscriber temporarily loses access to its event message stream, the optimized event message stream is determined using a shortest path graph search technique between the states defined by the start and end of the missing portion of the stream. Optimizations to the shortest path graph search technique are disclosed for use when the event interpretation rule is in replacement form, in which estimator functions based on extended rules are employed.

Abstract: There is utilized a particular bucket conveyor apparatus for the transport of fragile articles such as cookies and crackers from an input feed point to a multiple number of discharge areas. At the discharge areas the bucket conveyors are tilted rearwardly to spread the fragile crackers and cookies over a lower transverse belt or vibrating conveyor. In the operation of the apparatus each of the buckets is filled initially to less than about 50 percent of its volume. In this way if there is not an available discharge point, the bucket can once again go through the cycle before it would reach a point of overflowing. When the buckets are in a full condition, they will empty half or more of their contents onto a storage station conveyor prior to passing the input feed point. This bucket conveyor mechanism lends itself to a high degree of computerized control.