Methods of operating load balancing switches and controllers using modified flow entries

A load balancing switch comprising:

• a controller interface configured to provide communications with a load balancing controller;
• a server interface configured to provide communications with a plurality of servers;
• a network interface configured to provide communications with a plurality of client devices over a network;
• a memory configured to provide a flow table including a flow entry wherein the flow entry includes a match pattern that is satisfied by a data flow identification, and wherein the flow entry identifies a first server of the plurality of servers;
• a switch processor coupled to the controller interface, the server interface, the network interface, and the memory, the processor being configured to,
• receive a first data packet including a first data flow identification through the network interface,
• responsive to the first data flow identification satisfying the match pattern, transmitting the first data packet to the first server through the server interface,
• modify the flow entry to add an identification of a second server so that the flow entry identifies the first server and the second server, after transmitting the first data packet to the first server,
• receive a second data packet including a second data flow identification through the network interface after modifying the flow entry, and
• transmit the second data packet through the server interface to the first server and to the second server responsive to the second data flow identification satisfying the match pattern.

A load balancing controller comprising:

• a switch interface configured to provide communications with a load balancing switch including a flow table to define processing for received data packets;
• and
• a processor coupled to the switch interface, wherein the processor is configured to,
• transmit an instruction through the switch interface to install a flow entry in the flow table at the switch wherein the flow entry includes a match pattern that is satisfied by a flow identification, and wherein the flow entry identifies a first server of the plurality of servers, and
• after transmitting the instruction to install the flow entry, transmit an instruction through the switch interface to modify the flow entry in the flow table at the switch to add an identification of a second server so that the flow entry identifies the first server and the second server.