Abstract: A computer-implemented method, a computerized system and a product for providing a cluster of replicated servers. The method performed by a computerized server in a cluster of servers, wherein the cluster of servers are executing replicated instances of an application, wherein the replicated instances are configured to perform the same processing of the same input, comprising: detecting a message loss in the server; electively determining a responsive action to the message loss; and notifying the cluster of servers of the responsive action determined by the server, whereby other servers of the cluster of servers are able to mimic operation of the server by simulating the responsive action.

Abstract: A method for server replication in a network environment is provided. The primary server provides a first service to a client. If the first service involves interaction with a non-deterministic data source, the primary server performs the interaction and provides information about the interaction to a secondary server that is a replica of the primary server. The secondary server uses the information about the interaction to synchronize the secondary server with the primary server.

Abstract: Methods, apparatus, and products are disclosed for synchronizing an active feed adapter and a backup feed adapter in a high speed, low latency data communications environment that include brokering, by a stream administration server, establishment of an active message stream to a subscribing client device from an active feed adapter, the active message stream capable of communicating active application messages; brokering, by the server, establishment of a backup message stream to the client device from a backup feed adapter, the backup message stream capable of communicating backup application messages; receiving an active feed adapter state in backup messaging middleware of the backup adapter from active messaging middleware of the active adapter; determining, by the backup feed adapter, whether a backup feed adapter state is synchronized with the active feed adapter state; and administering, by the backup feed adapter, operation of the backup adapter in dependence upon the determining.

Abstract: A method of routing dependent messages sent from a source node. The method comprises routing a plurality of messages including a plurality of dependent messages from a source node for processing by a group of a plurality of processing nodes, optionally while managing a failure recovery mechanism and complying with message dependencies. Each message having a weight, each dependent message is routed while at least one dependency thereof is complied with, acquiring a plurality of acknowledge notifications to at least some of the plurality of messages from the plurality of processing nodes, calculating, at the source node using a processor, a message load of each of the plurality of processing nodes according to the weight of respective messages of plurality of messages which are sent thereto and respective acknowledge notifications of the plurality of acknowledge notifications which are sent therefrom. The routing is performed according to the respective message load.

Abstract: A method includes receiving active application messages that are part of an active message stream in a subscribing client device from an active feed adapter. Each active application message is characterized by an active source stream identifier, an active source stream sequence number, and an active message sequence number. The method includes receiving, in response to a failover from the active feed adapter to a backup feed adapter, backup application messages in the subscribing client device from the backup feed adapter. Each backup application message is characterized by a backup source stream identifier, a backup source stream sequence number, and a backup message sequence number. The method includes administering, by the subscribing client device, the backup application messages in dependence upon the active stream source identifier, the active stream source sequence number, the backup stream source identifier, and the backup stream source sequence number.

Abstract: Enhancing performance in a multicasting system comprising monitoring filtering costs in a multicasting system as system characteristics change over time, wherein the multicasting system is operating based on a first mapping, between a plurality of data flows and multicasting groups, to disseminate data to users that subscribe to one or more of the data flows; computing a second mapping in response to determining that overhead associated with filtering of unwanted flows at the user level has exceeded a threshold; and transitioning the multicasting system from using the first mapping to using the second mapping, in response to determining that the second mapping is feasible as applicable to one or more constraints associated with the multicasting system.

Abstract: A computer-implemented method, a computerized system and a product for providing a cluster of replicated servers. The method performed by a computerized server in a cluster of servers, wherein the cluster of servers are executing replicated instances of an application, wherein the replicated instances are configured to perform the same processing of the same input, comprising: detecting a message loss in the server; electively determining a responsive action to the message loss; and notifying the cluster of servers of the responsive action determined by the server, whereby other servers of the cluster of servers are able to mimic operation of the server by simulating the responsive action.

Abstract: A group communication service maintains synchronization limiting the group to the processing entities that receive a plurality of source message streams from sources outside the group and transmit delivery message streams to destinations that are outside the group. Synchronization of message ordering and other state synchronization directives are communicated from a leader exclusively to other group members. Once having declared themselves to be synchronized and active by a reply protocol message, which is an opaque object and is interpreted by an application layer, the processing entities independently process the source message streams in accordance with the order specified in the directives, without requiring additional sequencing information from another processing entity.

Abstract: A method, system and computer program product for transmitting data entities, the method includes: receiving data entities to be transmitted over multiple channels; and preventing a transmission of data entities that are to be transmitted over congested channels while transmitting data entities that are to be are to be transmitted over non-congested channels.

Abstract: A group communication service is adapted for multi-point to multi-point communication. Identical message streams are received by a tier of processing servers from a tier of sources. The processing servers deliver the message streams to a tier of destinations. The group communication service enables the processing servers to deal with newly added message streams and deleted message streams while preserving total ordering.

Abstract: A method includes receiving active application messages that are part of an active message stream in a subscribing client device from an active feed adapter. Each active application message is characterized by an active source stream identifier, an active source stream sequence number, and an active message sequence number. The method includes receiving, in response to a failover from the active feed adapter to a backup feed adapter, backup application messages in the subscribing client device from the backup feed adapter. Each backup application message is characterized by a backup source stream identifier, a backup source stream sequence number, and a backup message sequence number. The method includes administering, by the subscribing client device, the backup application messages in dependence upon the active stream source identifier, the active stream source sequence number, the backup stream source identifier, and the backup stream source sequence number.

Abstract: A method for communication in a computing environment is provided. The method comprises transmitting a first data packet to one or more receiving units in a first set; receiving one or more acknowledgement messages (ACKs) from one or more receiving units in a second set, wherein the second set is a subset of the first set; removing the first data packet from a queue, in response to receiving at least one ACK from N receiving units within a time threshold; and re-transmitting the first data packet to the first set, in response to failing to receive at least one ACK from N receiving units within the time threshold.

Abstract: Methods, apparatus, and products are disclosed for reliable messaging using redundant message streams in a high speed, low latency data communications environment that include brokering, by a stream administration server, establishment of an active message stream to a subscribing client device from an active feed adapter, the active message stream capable of communicating active application messages; brokering, by the server, establishment of a backup message stream to the subscribing client device from a backup feed adapter, the backup message stream capable of communicating backup application messages representing duplicates of the active messages; receiving the active messages in messaging middleware of the subscribing client device; receiving, in response to a failover, the backup messages in the messaging middleware; and administering, by the messaging middleware, the backup messages in dependence upon an active stream source identifier, an active stream source sequence number, a backup stream source ide

Abstract: Deallocating resources allocated to a network communications session, including extrapolating an expected location of a selected node that belongs to a communications path of a network communications session, determining if the extrapolated location is beyond a predefined range from a neighboring node that belongs to the communications path of the network communications session and that immediately neighbors the selected node along the communications path, and deallocating any resources allocated to the network communications session if the extrapolated location is beyond the range.

Abstract: A publish/subscribe system includes a publisher and multiple subscribers. The published includes a packet generator to generate a packet with at least one of: a fixed length flow label labeling a message or a message bundle and a fixed length node label labeling at least one message bundle and indicating at least one of the nodes of a topic tree to which the flow label belongs. Each received includes a user selection data holder and a message selector. The data holder stores a selection of topics of interest to a user from the topic tree. The message selector receives a packet having a header and data, determines which flow and/or node labels are incorporated in the header and accepts the data if the user selection data holder indicates that the labels within the header are of interest to the user.

Abstract: Methods, systems, and products are disclosed for filtering application messages in a high speed, low latency data communications environment that include: receiving an application message in a transport engine of a message receiving device from a message transmitting device, the application message having a message contents label and a collision indicator, the message contents label representing contents of the application message, the collision indicator specifying whether the message contents label represents different contents in at least one other application message; determining, by the transport engine, whether contents of the application message satisfy a transport layer constraint in dependence upon the message contents label; providing, by the transport engine, the application message and the collision indicator to messaging middleware of the message receiving device if the contents of the application message satisfy the transport layer constraint; and administering the application message, by the me

Abstract: A method for server replication in a network environment is provided. The primary server provides a first service to a client. If the first service involves interaction with a non-deterministic data source, the primary server performs the interaction and provides information about the interaction to a secondary server that is a replica of the primary server. The secondary server uses the information about the interaction to synchronize the secondary server with the primary server.

Abstract: Efficient Light-Weight Multicasting Communication Protocol A method for communication in a computing environment is provided. The method comprises transmitting a first data packet to one or more receiving units in a first set; receiving one or more acknowledgement messages (ACKs) from one or more receiving units in a second set, wherein the second set is a subset of the first set; removing the first data packet from a queue, in response to receiving at least one ACK from N receiving units within a time threshold; and re-transmitting the first data packet to the first set, in response to failing to receive at least one ACK from N receiving units within the time threshold.

Abstract: Deallocating resources allocated to a network communications session, including extrapolating an expected location of a selected node that belongs to a communications path of a network communications session, determining if the extrapolated location is beyond a predefined range from a neighboring node that belongs to the communications path of the network communications session and that immediately neighbors the selected node along the communications path, and deallocating any resources allocated to the network communications session if the extrapolated location is beyond the range.

Abstract: A method, system and computer program product for transmitting data entities, the method includes: receiving data entities to be transmitted over multiple channels; and preventing a transmission of data entities that are to be transmitted over congested channels while transmitting data entities that are to be are to be transmitted over non-congested channels