Abstract: To enable adaptive monitoring of the resource, metrics about the workload received at the resource from one or more clients are used to derive monitoring feedback comprising a recommendation as to how the monitoring should be performed. This is then used as input to a decision making process controlling the monitoring of the resource. The recommendation may be for the monitor to increase or decrease its monitoring interval. The resource may decide to increase or decrease its monitoring depth or checking, or may suggest a new monitoring depth to the monitor.

Abstract: The order of messages in an asynchronous message system is preserved, by generating a message and tagging the generated message with a sequence identifier and a sequence number. The order of messages is further preserved by processing the tagged message by checking a log to determine whether the sequence identifier is in the log, sending the tagged message to a selected consumer if the sequence identifier is not in the log and sending the tagged message to a particular consumer if the sequence identifier is in the log. Still further, the order of messages is preserved by writing an entry to the log having the sequence identifier and the sequence number of the tagged message and a consumer identifier of the selected consumer if the sequence identifier of the tagged message is not in the log.

Abstract: There is disclosed a method, apparatus and computer program for an application instance to request attachment to a queue partition on a messaging server within a plurality of messaging servers, each messaging server holding at least one queue partition, the set of queue partitions together forming a single queue. An application instance requests attachment to a queue partition, the request requesting exclusivity with regard to other application instances having a common identifier. Responsive to an indicating that the request has been successful, the application instance interacts with the queue partition.

Abstract: A method of routing messages to multiple consumers comprises determining a probability function defining message classification probabilities for each of a plurality of consumer sets, receiving a plurality of messages, classifying each message, storing each message in a queue, receiving notification of a consumer available to process a message, ascertaining the consumer set to which the available consumer belongs, accessing the probabilities for the ascertained consumer set, selecting a message classification according to the accessed probabilities, and transmitting a message, of the selected classification, to the available consumer.

Abstract: The order of messages in an asynchronous message system is preserved, by generating a message and tagging the generated message with a sequence identifier and a sequence number. The order of messages is further preserved by processing the tagged message by checking a log to determine whether the sequence identifier is in the log, sending the tagged message to a selected consumer if the sequence identifier is not in the log and sending the tagged message to a particular consumer if the sequence identifier is in the log. Still further, the order of messages is preserved by writing an entry to the log having the sequence identifier and the sequence number of the tagged message and a consumer identifier of the selected consumer if the sequence identifier of the tagged message is not in the log.

Abstract: Order associated with messages is preserved in an environment wherein a message includes an associated order identifier; a receiver is operable to receive a first message associated with a first order identifier and a selection component is operable to select a first entity for processing the first message. The system includes a determination component for determining whether a notification associated with completion of processing of the first message has been received by the receiver; and a controller for controlling the selection component to select a second entity for processing the second message, in response to a combination of receipt of the notification and a second message associated with the first identifier being received by the receiver preceding the receipt of the notification.

Abstract: Messages are redistributed in a clustered messaging environment including messaging servers and consuming applications. Each messaging server has a queue partition operable to contain messages. Each consuming application can connect to a messaging server in to consume one or more messages from a queue partition local to that messaging server. A message on a holding queue partition local to a messaging server without at least one consumer interested in consuming that message is said to be marooned. A marooned message is redistributed from the holding queue partition to a messaging server that does have at least one consumer interested in consuming the message. The redistribution involves identifying a group of servers, each of which has one or more consumers interesting in consuming the message, selecting a server from the group and forwarding the message to the selected server.

Abstract: A method of synchronization for use in a distributed data processing system comprising a legacy computer having means for storing a master version of data, an application server, and a thin client computer which stores a copy of the master version of data. Firstly, the thin client executes operations locally on the copy. The operations are sent in a list to the application server. The application server executes the operations on the master data, on behalf of the thin client. If the operations can be executed successfully on the master version, synchronization occurs in that the successful operations are applied to the master version.

Abstract: A quorum-based server power-down mechanism allows a manager in a computer cluster to power-down unresponsive servers in a manner that assures that an unresponsive server does not become responsive again. In order for a manager in a cluster to power down servers in the cluster, the cluster must have quorum, meaning that a majority of the computers in the cluster must be responsive. If the cluster has quorum, and if the manager server did not fail, the manager causes the failed server(s) to be powered down. If the manager server did fail, the new manager causes all unresponsive servers in the cluster to be powered down. If the power-down is successful, the resources on the failed server(s) may be failed over to other servers in the cluster that were not powered down. If the power-down is not successful, the cluster is disabled.

Abstract: A quorum-based server power-down mechanism allows a manager in a computer cluster to power-down unresponsive servers in a manner that assures that an unresponsive server does not become responsive again. In order for a manager in a cluster to power down servers in the cluster, the cluster must have quorum, meaning that a majority of the computers in the cluster must be responsive. If the cluster has quorum, and if the manager server did not fail, the manager causes the failed server(s) to be powered down. If the manager server did fail, the new manager causes all unresponsive servers in the cluster to be powered down. If the power-down is successful, the resources on the failed server(s) may be failed over to other servers in the cluster that were not powered down. If the power-down is not successful, the cluster is disabled.

Abstract: A method of routing messages to multiple consumers comprises determining a probability function defining message classification probabilities for each of a plurality of consumer sets, receiving a plurality of messages, classifying each message, storing each message in a queue, receiving notification of a consumer available to process a message, ascertaining the consumer set to which the available consumer belongs, accessing the probabilities for the ascertained consumer set, selecting a message classification according to the accessed probabilities, and transmitting a message, of the selected classification, to the available consumer.

Abstract: In a client/server network, a client may be able to use any of several servers in accomplishing a particular task but may still have preferences as to which server should, if available, be used. If the preferred server is not available, the client will be connected to an alternate server. If a server having a higher preference than the alternate server becomes available, state information associated with the client session with the alternate server is used in order to decide when the client may be switched to the preferred server without compromising work currently being done.

Abstract: A quorum-based server power-down mechanism allows a manager in a computer cluster to power-down unresponsive servers in a manner that assures that an unresponsive server does not become responsive again. In order for a manager in a cluster to power down servers in the cluster, the cluster must have quorum, meaning that a majority of the computers in the cluster must be responsive. If the cluster has quorum, and if the manager server did not fail, the manager causes the failed server(s) to be powered down. If the manager server did fail, the new manager causes all unresponsive servers in the cluster to be powered down. If the power-down is successful, the resources on the failed server(s) may be failed over to other servers in the cluster that were not powered down. If the power-down is not successful, the cluster is disabled.

Abstract: A quorum-based server power-down mechanism allows a manager in a computer cluster to power-down unresponsive servers in a manner that assures that an unresponsive server does not become responsive again. In order for a manager in a cluster to power down servers in the cluster, the cluster must have quorum, meaning that a majority of the computers in the cluster must be responsive. If the cluster has quorum, and if the manager server did not fail, the manager causes the failed server(s) to be powered down. If the manager server did fail, the new manager causes all unresponsive servers in the cluster to be powered down. If the power-down is successful, the resources on the failed server(s) may be failed over to other servers in the cluster that were not powered down. If the power-down is not successful, the cluster is disabled.

Abstract: A quorum-based server power-down mechanism allows a manager in a computer cluster to power-down unresponsive servers in a manner that assures that an unresponsive server does not become responsive again. In order for a manager in a cluster to power down servers in the cluster, the cluster must have quorum, meaning that a majority of the computers in the cluster must be responsive. If the cluster has quorum, and if the manager server did not fail, the manager causes the failed server(s) to be powered down. If the manager server did fail, the new manager causes all unresponsive servers in the cluster to be powered down. If the power-down is successful, the resources on the failed server(s) may be failed over to other servers in the cluster that were not powered down. If the power-down is not successful, the cluster is disabled.

Abstract: There is disclosed a method, apparatus and computer program for an application instance to request attachment to a queue partition on a messaging server within a plurality of messaging servers, each messaging server holding at least one queue partition, the set of queue partitions together forming a single queue. An application instance requests attachment to a queue partition, the request requesting exclusivity with regard to other application instances having a common identifier. Responsive to an indicating that the request has been successful, the application instance interacts with the queue partition.

Abstract: Messages are redistributed in a clustered messaging environment including messaging servers and consuming applications. Each messaging server has a queue partition operable to contain messages. Each consuming application can connect to a messaging server in to consume one or more messages from a queue partition local to that messaging server. A message on a holding queue partition local to a messaging server without at least one consumer interested in consuming that message is said to be marooned. Using either a push model or a pull model, a marooned message is redistributed from the holding queue partition to a queue partition local to a messaging server that does have at least one consumer interested in consuming the message.

Abstract: Provided are methods and computer programs for managing installation of a set of data processing components. An installation manager program allows users to specify which of a set of predefined functional roles are to be implemented on which of their data processing systems and then the installation program automates installation of the set of data processing components which correspond to the specified roles.

Abstract: Disclosed are a method, apparatus, and computer program for, in an end-user computer environment, reversing an effect of an autonomously-initiated program action, by recognizing that the program action is to be performed, recording data representing a state change caused by the program action, providing a user option to cause the computer system to reverse the state change caused by the program action, responsive to a user selection of the user option, retrieving the data representing a state change, and reversing the state change caused by the program action.

Abstract: Provided are methods and computer programs for managing installation of a set of data processing components. An installation manager program allows users to specify which of a set of predefined functional roles are to be implemented on which of their data processing systems and then the installation program automates installation of the set of data processing components which correspond to the specified roles.