System and method for ensuring delivery of a single communication between nodes

A computer readable storage medium storing instructions that, when executed by a computer, cause the computer to perform a method of delivering a message from a first node to a second node in a multi-node computing environment, the first node including a first memory and the second node including a second memory, wherein said first memory and said second memory are configured to store identifiers associated with a subset of messages generated by the first node for delivery to the second node, the method comprising the steps of:

• generating a first message from the first node toward the second node;
• selecting a first identifier for said first message;
• attempting to transmit said first message from the first node to the second node;
• if said first message is received at the second node:
• searching said second memory for said first identifier;
• and
• if said first identifier does not match any identifier stored in said second memory, updating a status memory on the second node, wherein said status memory is configured to indicate delivery statuses of multiple messages generated by the first node for the second node;
• sending a query message from the first node to the second node to determine if said first message was received by the second node, wherein said query message includes said first identifier;
• and
• sending a repeat of said first message from the first node to the second node if a response to said query message is negative, wherein an identifier different from said first identifier is associated with said repeat message.

A system for ensuring delivery of a message from a first computer node to a second computer node, comprising:

• a first node configured to generate a message for a second node, wherein said message has an identifier, said first node comprising:
• a communication module configured to attempt to transmit said message toward said second node;
• a first memory configured to store a delivery status of said message;
• and
• a second memory configured to store identifiers of a subset of messages transmitted by said first node toward said second node;
• wherein said first node receives a receipt status of said message from said second node;
• and
• wherein said identifier of said message is stored in said second memory if said receipt status is negative.

A method of sending a communication from a first node to a second node in a multi-node computing environment, comprising the steps of:

• generating a communication on a first node for transmission to a second node;
• selecting an identifier;
• comparing said identifier to a set of unusable identifiers;
• associating said identifier with said communication if said identifier is not included in said set of unusable identifiers;
• attempting to transmit said communication to the second node;
• sending a query to the second node to determine if the second node received said communication;
• and
• if a response to said query is negative:
• storing said identifier in said set of unusable identifiers.

A system for ensuring delivery of a communication from one computer node to another computer node, comprising:

• a first node, comprising:
• a first memory configured to store a first identifier for association with a first communication sent from said first node;
• and
• a second memory configured to store a set of unusable identifiers associated with communications rescinded by said first node, wherein said first identifier is compared against each of said unusable identifiers before being associated with said first communication;
• and
• a second node, comprising:
• a first memory configured to store statuses of a first set of communications generated by said first node, wherein each said status indicates whether a corresponding communication was received by said second node and whether said corresponding communication was rescinded by said first node;
• and
• a second memory configured to indicate whether any of a second set of communications generated by said first node were rescinded by said first node, wherein none of the communications in said second set were received by said second node;
• wherein said first set of communications and said second set of communications are mutually exclusive;
• wherein said first communication is rescinded by said first node if, before said second node receives said first communication, said second node is queried by said first node as to whether said second node received said first communication;
• and
• wherein said first identifier becomes an unusable identifier if said first communication is rescinded by said first node.

A computer readable storage medium containing a data structure configured for indicating a status of a communication generated by a first node for a second node, the data structure comprising:

• a first segment of computer manipulable memory, said segment comprising:
• a series of status entries, wherein each of said entries corresponds to a single communication generated by the first node for delivery to the second node, each entry comprising:
• a first indicator configured to indicate whether a communication corresponding to said entry was received by the second node;
• and
• a second indicator configured to indicate whether said communication corresponding to said entry was rescinded by the first node;
• wherein said series of status entries is indexed by identifiers ranging from a lower identifier to an upper identifier, said identifiers configured to identify said communications corresponding to said status entries;
• and
• wherein a second segment of computer manipulable memory is logically adjoined to said first segment if a first communication received from the first node is associated with a first identifier not within said range of said lower identifier to said upper identifier.

A computer readable storage medium storing instructions that, when executed by a computer, cause the computer to perform a method of sending a communication from a first node to a second node in a multi-node computing environment, the method comprising the steps of:

• generating a communication on a first node for transmission to a second node;
• selecting an identifier;
• comparing said identifier to a set of unusable identifiers;
• associating said identifier with said communication if said identifier is not included in said set of unusable identifiers;
• attempting to transmit said communication to the second node;
• sending a query to the second node to determine if the second node received said communication;
• and
• if a response to said query is negative:
• storing said identifier in said set of unusable identifiers.

A method of ensuring receipt of a communication from a first node at a second node in a multi-node computing environment, comprising:

• receiving a first communication from a first node at a second node;
• retrieving from said first communication an identifier of said first communication;
• comparing said identifier to a set of rescinded identifiers;
• if said identifier matches one of said rescinded identifiers, discarding said first communication;
• and
• if none of said rescinded identifiers match said identifier, updating a status memory configured to indicate statuses of multiple communications generated by the first node, including said first communication.