VM Live Migration Flow Caching for Faster TCP Session Recovery

The patent applies preliminary action by establishing a flow cache mechanism before the virtual machine suspension. The flow cache pre-prepares to store incoming data packets, so when the VM is suspended and memory is being copied, network traffic is not lost but temporarily held. This allows the VM to be suspended for the necessary time to ensure memory copying accuracy without permanently losing network connectivity, as the cached packets can be delivered after resumption.

The flow cache acts as an intermediary between the network and the virtual machine during suspension. Instead of directly losing packets when the VM is suspended, the flow cache mediates by temporarily storing incoming packets and forwarding them after the VM resumes. This intermediary mechanism decouples the network traffic flow from the VM's operational state, allowing the VM to be suspended for state consistency without directly impacting network connection restoration time.

The flow cache performs preliminary action by pre-storing incoming data packets before the VM suspension completes and before TCP timeout retransmission would be triggered. When the VM resumes, the cached packets are immediately available for delivery, which can prevent or reduce the need for TCP timeout retransmission. This preliminary caching action maintains connection reliability while significantly reducing the time penalty that would otherwise be incurred through TCP timeout mechanisms.