Method for flow control and for reliable communication in a collaborative environment

A method for reliable messaging between a service and a client, comprising:

• listening, at the client, for periodic keep alive messages that are communicated by the service on a first half-duplex channel;
• listening, at the service, for periodic keep alive messages that are communicated by the client on a second half-duplex channel;
• communicating messages between the client and the sever over the first half-duplex channel and the second half-duplex channel, wherein each message contains a unique message sequence number;
• communicating a sequence acknowledgement message between the client and the service in response to the messages over the first half-duplex channel and the second half-duplex channel, the sequence acknowledgement message containing the unique message sequence number that was last successfully received by the service and the client;
• detecting a communication failure on the first half-duplex channel or the second half-duplex channel if the periodic keep alive messages are not received at the client after a predetermined period of time in order to determine that the first half-duplex channel or the second half-duplex channel on which the keep alive messages have not been received has failed;
• reestablishing, by the client, communication with the service over a new first half-duplex channel or a new second half-duplex channel in accordance with the detecting;
• and
• communicating, by the service, messages over the first half-duplex channel or the new first half-duplex channel beginning with a unique sequence number that is after a unique sequence number associated with a last sequence acknowledgement message received by the service.

A method for reliable messaging between a service and a client, comprising:

• listening, at the client, for periodic keep alive messages that are communicated by the service on a first half-duplex channel;
• listening, at the service, for periodic keep alive messages that are communicated by the client on a second half-duplex channel;
• communicating messages from the client to the service over the second half-duplex channel in response to associated previous messages communicated from the service to the client, wherein each message contains a unique message sequence number;
• detecting a communication failure on the first half-duplex channel or the second half-duplex channel if the periodic keep alive messages are not received at the client after a predetermined period of time in order to determine that the first half-duplex channel or the second half-duplex channel on which the keep alive messages have not been received has failed;
• reestablishing, by the client, communication with the service over a new first half-duplex channel or new second half-duplex channel in accordance with the detecting;
• and
• resuming communicating messages from the client to the service over the second half-duplex channel or the new second half-duplex channel in accordance with a last unique message sequence number received by the client.