Episodic coordination model for distributed applications

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.

主权项

1. A computer system, comprising:
a processor; and system memory storing instructions for managing messages exchanges between a sender and a destination that, when executed by the processor as part of the sending of an outgoing message, cause the computer system to:
move to a sending state from an idle state maintained when the outgoing message is identified as ready to send;send the outgoing message to the destination while in the sending state;wait in the sending state until an acknowledgement message is received from the destination, wherein the acknowledgement message indicates that the destination has received the outgoing message;move to a confirming state from the sending state, without returning to the idle state, when the acknowledgement message is received;send a confirmation message to the destination while in the confirming state, wherein the confirmation message indicates that the sender has received the acknowledgment message;wait in the confirming state until a confirmation-acknowledgement message is received from the destination, wherein the confirmation-acknowledgement message indicates that the destination has received the confirmation message; andmove to the idle state from the confirming state when the confirmation-acknowledgement message is received.