Flow-Based Local Egress in Multisite Datacenters

The patent applies preliminary action by pre-establishing flow affinity bindings between data flows and egress edges before workload migration occurs. The system records the original egress edge association for each data flow in advance, enabling direct routing decisions after migration without requiring traffic to return to the original site. This proactive binding establishment resolves the contradiction by maintaining stateful service requirements while preventing tromboning effects.

The patent introduces an intermediary mechanism in the form of a flow affinity binding table that mediates between migrated workloads and original egress edges. This intermediary structure stores forwarding information and enables direct routing without requiring traffic to physically return to the original datacenter site. The binding table acts as a mediator that preserves stateful service associations while eliminating the inefficiencies of tromboning traffic patterns.

The system performs preliminary action by establishing flow affinity bindings before workload migration, recording the relationship between data flows and their original egress edges. This pre-established binding information enables direct routing decisions after migration, eliminating the need for packets to traverse interconnect links multiple times. The preliminary binding establishment preserves NAT bindings while avoiding the time loss associated with tromboning traffic patterns.

The patent applies segmentation by separating the control plane function (maintaining flow affinity bindings) from the data plane traffic flow. The binding information is segmented and stored in a dedicated forwarding information structure, allowing traffic to be routed directly based on pre-recorded associations without requiring repeated traversal through the interconnect. This segmentation preserves stateful service requirements while minimizing latency.