Migrating connection flows

摘要

In a cluster network, an ingress component can serve as an entry point for incoming request traffic and route requests to a plurality of backend servers for processing. Each of the backend servers can handle multiple flows (e.g., TCP) established with the ingress component. When a backend server is detected to have been overloaded with requests, a different peer server is selected on the network to take over processing of the requests from the overloaded server. A set of state information for at least one connection is then transferred from the overloaded server to the selected peer server. Thereafter, the ingress component can update its routing information to begin routing new incoming requests or packets for that connection to the new peer server. The state information can be transferred upon reaching a logical boundary between requests, or within a request, received on the connection.

主权项

1. A computer-implemented method for moving connections from a computing device, said method comprising:
establishing a plurality of transmission control protocol (TCP) connections between an ingress component and a plurality of backend servers; receiving, by said ingress component, a plurality of requests from a client and forwarding the requests from the ingress component to the plurality of backend servers over the plurality of TCP connections; detecting that a first backend server of the plurality of backend servers has been overloaded by processing at least a portion of the forwarded requests; selecting a second backend server from the plurality of backend servers to take over processing from said first backend server; causing a set of state information associated with at least one TCP connection that was established on the first backend server to be transferred to the second backend server, wherein the set of state information includes at least an acknowledgement counter and a sequence number to be sent to the client; and routing, to the second backend server, subsequent requests associated with said at least one TCP connection received by the ingress component from the client.