Issues of Mobile Agent Communication • The receiver agent may migrate to another peer • How does the sender agent know the receiver agent has migrated? • How does the sender agent know the latest location of the receiver agent? • Message reliability • The receiver agent may crash when the peer it resides crash. How to ensure that the receiver agent does not miss any message?
Receiver agent Sender agent MCP C MCP A MCP B Receiver agent migrated before sender agent tries to communicate with it Communication request Target agent is not here
Agent B Agent A MCP C / HCP of agent C MCP A / HCP of agent A MCP B / HCP of agent B Receiver agent crashed before sender agent tries to communicate with it Sending message Connection failed
Mechanism for solving the mobile agent migration issue • Terms • MCP – Mobile Context Peer • When a mobile agent migrates from MCP A to MCP B, the mobile agent sends a message to MCP A to update its new location. • The agent can also publish its new location to the overlay network • Before making a communication, the sender agent finds the current location of the receiver agent
Receiver agent Sender agent MCP C MCP A MCP B Mechanism for solving the mobile agent migration issue Communication request Update its new location Forward communication request
Mechanism for solving the message reliability issue • Terms • MCP – Mobile Context Peer • HCP – Home Context Peer • Every MCP in the overlay system provides the “messaging-queue service” • The HCP of a mobile agent serves as the messaging-queue server of the mobile agent • The mobile agent publishes its HCP to the overlay network • Every message sent to a mobile agent will also be sent to its HCP if there is an error while sending the message • The message-queue will be checked when the mobile agent re-starts and then periodically
Agent B Agent A MCP C / HCP of agent C MCP A / HCP of agent A MCP B / HCP of agent B Mechanism for solving the message reliability issue Send message Check the message queue when re-starts, and then periodically Connection failed Retrieved the lost messages. Send message