44 results about "Reliable messaging" patented technology

The subject invention provides reliable messaging with and within a control environment. The systems and methods utilize a message broker that facilitates message exchange. The message broker can be located within an industrial controller, as a dedicated entity within a control environment and/or an entity external to the control environment. Messages transmitted from an industrial controller and/or the external entity can be routed through the message broker prior to reaching a destination, wherein the message can be stored in the message broker and subsequently obtained by a recipient. The message broker decouples the message sender (e.g., an industrial controller, an external entity . . . ) from the message recipient (e.g., an industrial controller, an external entity . . . ) such that messages can be successfully transmitted (to the message broker) regardless of a state of the recipient, and messages can be retrieved (from the message broker) regardless of a state of the sender.

The present invention guarantees that messages in a distributed computing environment are successfully delivered from an application sending data to an application receiving the data by maintaining a fault tolerant message delivery system in the event of system failure. This method of reliable message delivery uses at least four separate computing devices that communicate with each other via a Local Area Network. Each computing device has its own Receiver, Message Queue, and Transmitter, referred to as a Node, which are used for message transport. Each message is held in at least two Message Queues on two computing devices at one time until the message is successfully delivered to its final destination.

Methods, apparatus, and products are disclosed for reliable messaging using a message stream 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; receiving, in a transport engine of the subscribing client device from the active feed adapter on an active message stream, active application messages encapsulated in active transport packets; receiving, by the transport engine from the active feed adapter, an active transport packet containing an active mapping; identifying, by the transport engine in dependence upon active sequence numbers, a missing active transport packet; identifying, by the transport engine, missing active application messages of the missing active transport packet in dependence upon the active mapping; and requesting, by the transport engine, transmission of the missing active application messages from the active feed adapter.

The present invention provides for flow and congestion control mechanisms in accordance with a Reliable Message protocol for Web Services (RM-WS). For flow control, one endpoint informs another endpoint of its available buffer size by including buffer size information in response messages. The response messages, typically RM-WS infrastructure messages, are then used to determine an upper limit on the number of messages that can be sent to the acceptor in order to prevent resending messages due to buffer overrun. In the case of congestion control, embodiments provide for increasing the number of in-flight messages until a failure point is found. The last successful rate below the failure point is the closest known point to the optimum point. Example embodiments then reset and try again raising the rate back to the last known good point and fine tuning from there using an algorithm that asymptotes the optimum rate.

A reliable messaging channel is created using multiple independent HTTP requests. In one embodiment, a method (a) establishes a session identifier by exchanging messages with a recipient using an application layer communication protocol (e.g., HTTP); and (b) uses the application layer communication protocol to send ordered data to the recipient by assigning one or more sequence numbers according to the predetermined order in the data. The session identifier may be generated, for example, using a random number of generator. In one implementation, the session identifier is not less than 96 bits long. The sender may receive from the recipient acknowledgements each acknowledging receipt of the data bearing a corresponding sequence number. Data to be sent in the opposite direction may piggy-back on an acknowledgement by including the data in a non-zero length payload. Data received out of order are queued. The sender may limit the rate at which data is transmitted to a “window size” (i.e., no more than a predetermined amount of data is sent within a predetermined time period). The window size is adjusted according to a channel condition (e.g., an amount of data retransmitted or lost during the predetermined time period). In one implementation, the window size is adjusted by doubling or halving, consistent with the channel condition.

A system and method are provided for transmitting messages from a sender to a receiver via a communication network. Messages are received at the sender to transmit to the receiver, each of the messages having a predefined reliability mode. The predefined reliability mode for each of the messages is identified and the message is transmitted to the receiver in accordance with a protocol defined for the corresponding predefined reliability mode of the message.

A message flow controller limits a process from passing a new message in a reliable message passing layer from a source node to at least one destination node while a total number of in-flight messages for the process meets a first level limit. The message flow controller limits the new message from passing from the source node to a particular destination node from among a plurality of destination nodes while a total number of in-flight messages to the particular destination node meets a second level limit. Responsive to the total number of in-flight messages to the particular destination node not meeting the second level limit, the message flow controller only sends a new packet from among at least one packet for the new message to the particular destination node while a total number of in-flight packets for the new message is less than a third level limit.

A system, method, and computer readable medium for asynchronous live migration of applications between two or more servers. The computer readable medium includes computer-executable instructions for execution by a processing system. Primary applications runs on primary hosts and one or more replicated instances of each primary application run on one or more backup hosts. Asynchronous live migration is provided through a combination of process replication, logging, barrier synchronization, checkpointing, reliable messaging and message playback. The live migration is transparent to the application and requires no modification to the application, operating system, networking stack or libraries.

Methods, apparatus, and products are disclosed for reliable messaging using message streams in a high speed, low latency data communications environment that include: receiving, in a transport engine of a message receiving device from an active message sending device, active transport packets on an active message stream established from the active message sending device to the message receiving device, the active message sending device encapsulating active application messages in the active transport packets; identifying, by the transport engine, a missing active application message from the active message sending device; and requesting, by the transport engine from a backup message sending device, transmission of a backup application message that corresponds to the missing active application message, the backup message sending device encapsulating backup application messages in backup transport packets for transmission on a backup message stream, each backup application message representing a duplicate of a corresponding active application message.

A system for event-driven live migration of applications between two or more servers. Primary applications runs on primary hosts and one or more replicated instances of each primary application run on one or more backup hosts. Event driven live migration is provided through a combination of process replication, logging, barrier synchronization, reliable messaging and message playback. The event driven live migration is transparent to the application and requires no modification to the application, operating system, networking stack or libraries.

A system, method, and computer readable medium for asynchronous live migration of applications between two or more servers. The computer readable medium includes computer-executable instructions for execution by a processing system. Primary applications runs on primary hosts and one or more replicated instances of each primary application run on one or more backup hosts. Asynchronous live migration is provided through a combination of process replication, logging, barrier synchronization, checkpointing, reliable messaging and message playback. The live migration is transparent to the application and requires no modification to the application, operating system, networking stack or libraries.

The present disclosure relates generally to techniques for improving reliability of message communications. In certain embodiments, techniques are described for facilitating reliable communication of messages between a source (e.g., a client system) and a destination (e.g., a target system) via an intermediary communication handler system. In certain embodiments, a message can include a request to be communicated to a destination for a target service. An intermediary communication handler system can store information indicative of the delivery status for a message to ensure reliable communication. The information indicative of the delivery status for a message can be managed in association with a unique identifier corresponding to the message. The information indicative of the delivery status for a message may also be used to determine whether to retry communication of a message in satisfaction of reliability parameters (e.g., QoS criteria) specified for a communication protocol used for communication of the message.

A system and method for reliable messaging is provided. Instead of returning a message as undeliverable, the message is routed to a relay server. The relay server attempts to re-send or re-route the message to the destination server. Once the destination server and associated connection becomes operational, the relay server provides the message to the destination server. If the attempts to re-send or re-route the message time out or do not succeed after a certain number of attempts, the relay server may invoke a process to create another messaging server. The other messaging server substitutes for the original destination server and processes the message for the receiving user. In either situation, the message is provided to the receiving user.

A system and method are provided to perform tentative updating for transactions suing the Web Services Reliable Messaging protocol. From a protocol layer of a client side web services framework persists a message from an application transaction (a reversion message) in a persistent storage unit. The web services framework forwards the reversion message as a reliable message to a transport layer to cause a recipient to revert to a state prior to the application transaction, if a triggering event occurs in the web services framework. If no triggering event occurs a confirmation message is forwarded as a reliable message to confirm receipt of the tentative update at the transport layer. Concurrently with the confirmation persisted reversion message is deleted from the persistent storage unit.

A method and system to communicate reliably using messages in a communications network is described. Using the described method, a service provider and a service consumer communication using web services messages can track messages using an instance of a reliable messaging protocol to track message receipt. Using a messaging system independent from a web services runtime environment of the service provider or consumer, the system is able to provide additional services such as queuing, scheduling, and delivery quality of service.

The invention relates to a server current limiting method based on ZooKeeper, a system, a server and a storage medium, wherein the method establishes three nodes in the zookeeper, records tasks, executes information and wait information respectively, and listens for a change event of a node on the zookeeper and processes the corresponding event. ZooKeeper guarantees distributed data consistency and provides a reliable messaging mechanism to ensure that the current can be limited and merged into the waiting queue when the service is in high traffic.

A "high availability" system comprises multiple switches under the control of multiple control processors ("CPs"). One of the CPs is "active," while the other CP is in a "standby" mode. Upon detection of a failure of the active CP, fail-over occurs to the standby CP. The standby CP re-issues all messages that the previously active CP had issued and which had not yet completed when the fail-over occurred. The newly active CP uses a different range of transaction identifiers ("XIDs") than its predecessor CP. By using a different range of XID values, the newly active CP determines whether an incoming response message is responsive to a message that originated from the previously active CP or the newly activated CP. The currently active CP ignores all response messages that do not have an XID in its range, thereby ensuring proper and reliable messaging.