摘要:
An episodic execution of program instances and a coordinated message exchange protocol are combined to achieve eventual consistency in the communication between nodes of a distributed system. Program instances run in episodic loops that are triggered by defined input events and that generate checkpoints. The checkpoints indicate when messages are to be sent from the one instance to another instance or other device. The coordinated message exchange protocol allows the instance to send a message to a receiver, to acknowledge that the message has been received, and to confirm the acknowledgement to the receiver.
摘要:
A method and system for previewing and printing customized pages, such as business forms including invoices and billing statements. An author-created template has HTML and OLE components (controls) placed on a page to define a visual representation of a class of object that is part of a database. The controls merge data from a selected current object of the database into the template, producing a visual representation of the object that is both viewable and printable. An extension to the present invention involves the use of multiple-page HTML to dynamically provide subsequent pages based on retrieved data. For example, if the data retrieved by the controls for an invoice is too large to display on a single invoice page, another HTML page, that is different from the first page of the invoice, would be automatically loaded as a template and the overflow data properly merged therewith.
摘要:
A rendezvous abstraction that is used to correlate messages within message exchange. The rendezvous abstraction may be instantiated to correlate messages regardless of the type of message exchange pattern, and regardless of the underlying protocols used to communication message. Messages exchanges of primitive protocols are modeled as unilateral message exchanges. The rendezvous abstraction is used to correlate messages of the unilateral message exchange, and serves as an abstraction that is used to represented the rendezvous point where the message of the message exchange pattern are handled. Accordingly, instead of focusing on the protocol-specific mechanisms for correlation, if even available, the application author may simply work with a standard rendezvous abstraction.
摘要:
The present invention extends to methods, systems, and computer program products for coordinating application sate and communication mediums state. Embodiments of present invention provide a mechanism for a communication medium to provide a view of message content for a message (a peek) to an application along with the communication medium preventing further access to the message (a lock) until the application signals back how to handle the message. Thus, the communication medium indicates that the message is locked for the duration of processing at the application. Indicating that the message is locked significantly reduces the chance of the message being provided to another application (or another consumer of the same application) during the time the application is processing the view of message content.
摘要:
A reliable request-response mechanism allows a requesting computer system and a responding computer system in an established end-to-end connection to send and receive messages in a manner that the responding computer system processes a request as intended by the requesting computer system, such that all the message communication is initiated by the requesting computer system. The requesting computer system and responding computer system can accommodate a wide range of messaging failures, such as intermittent network connections or failure of a transport of SOAP intermediary by resending cached versions of previously sent messages, and by acknowledging receipt of each message received. Cached messages on either computer system are deleted after being appropriately acknowledged. After all sent messages have been acknowledged by the responding computer, and the requesting computer has received all of the response messages from the responding computer, the end-to-end connection is terminated with an exchange of connection termination messages.
摘要:
A distributed instance system manages instances and communications between the instances. The distributed instance system provides a restricted set of communication methods to the instances. Based on the type of communication method used, the distributed instance system has knowledge of the messages sent by instances and can make decisions on how to handle the messages. When one of the instances involved in a message exchange ends, the host uses its knowledge of the message exchange type to determine whether to drop the message, drop a reply to the message, and/or send an error message to the surviving instance. An instance may create one or more child instances in a tree-like configuration. Status data is passed up the tree from children instances and aggregated in the parent instances. Monitoring data may be generated from the aggregated status data.
摘要:
A distributed instance system manages instances and communications between the instances. The distributed instance system provides a restricted set of communication methods to the instances. Based on the type of communication method used, the distributed instance system has knowledge of the messages sent by instances and can make decisions on how to handle the messages. When one of the instances involved in a message exchange ends, the host uses its knowledge of the message exchange type to determine whether to drop the message, drop a reply to the message, and/or send an error message to the surviving instance. An instance may create one or more child instances in a tree-like configuration. Status data is passed up the tree from children instances and aggregated in the parent instances. Monitoring data may be generated from the aggregated status data.
摘要:
A rendezvous abstraction that is used to correlate messages within message exchange. The rendezvous abstraction may be instantiated to correlate messages regardless of the type of message exchange pattern, and regardless of the underlying protocols used to communication message. Messages exchanges of primitive protocols are modeled as unilateral message exchanges. The rendezvous abstraction is used to correlate messages of the unilateral message exchange, and serves as an abstraction that is used to represented the rendezvous point where the message of the message exchange pattern are handled. Accordingly, instead of focusing on the protocol-specific mechanisms for correlation, if even available, the application author may simply work with a standard rendezvous abstraction.
摘要:
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.
摘要:
The present invention monitors the receipt of messages between two endpoints on established sequence session in accordance with a Reliable Messaging protocol for Web Services (RM-WS protocol). The messages received may be application or infrastructure messages (e.g., acknowledgement messages in accordance with the RM-WS protocol). Further, the present invention defines a time period known as the inactivity timeout, which is an upper limit to the time that may pass without receiving a message (either application or infrastructure) on the sequence session. Based on this inactivity timeout period, the present invention calculates time periods for sending idempotent infrastructure messages in accordance with the RM-WS protocol for verifying and maintaining connection liveliness.