Method and apparatus for routing data to a load balanced server using MPLS packet labels

A method of routing data from a client to a selected load-balanced server among a plurality of servers in a network that comprises a plurality of load-balancing nodes, the method comprising the steps of:

• receiving a first packet of a client request at one of the load-balancing nodes in the network;
• performing a load-balancing decision to result in selecting one of the plurality of servers to receive the client request;
• storing information identifying a flow associated with the first packet, an identifier of an interface of that node on which the first packet arrived, and an outgoing interface identifier;
• receiving a first packet of a server reply at a last node associated with a selected server among the plurality of servers;
• receiving one or more subsequent packets of the client request;
• receiving an MPLS label value;
• storing the MPLS label value in a load balancing mapping at the last node that associates the MPLS label with the flow and interface identifying information;
• and
• forwarding the subsequent packets to the selected server on a route that is defined by the load-balancing mapping and without hop-by-hop routing decision.

A computer-readable medium carrying one or more sequences of instructions for routing data from a client to a selected load-balanced server among a plurality of servers in a network that comprises a plurality of load-balancing nodes, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

• receiving a first packet of a client request at one of the load-balancing nodes in the network;
• storing information identifying a flow associated with the first packet, an identifier of an interface of that node on which the first packet arrived, and an outgoing interface identifier;
• receiving a first packet of a server reply at a last node associated with a selected server among the plurality of servers;
• receiving one or more subsequent packets of the client request;
• receiving a label value;
• storing the label value in a load balancing mapping at the last node that associates the label with the flow and interface identifying information;
• and
• forwarding the subsequent packets to the selected server on a route that is defined by the load-balancing mapping and without hop-by-hop routing decisions.

An apparatus for routing data from a client to a selected load-balanced server among a plurality of servers in a network that comprises a plurality of load-balancing nodes, comprising:

• means for receiving a first packet of a client request at one of the load-balancing nodes in the network;
• means for storing information identifying a flow associated with the first packet, an identifier of an interface of that node on which the first packet arrived, and an outgoing interface identifier;
• means for receiving a first packet of a server reply at a last node associated with a selected server among the plurality of servers;
• means for receiving one or more subsequent packets of the client request;
• means for receiving a label value;
• means for storing the label value in a load balancing mapping at the last node that associates the label with the flow and interface identifying information;
• and
• means for forwarding the subsequent packets to the selected server on a route that is defined by the load-balancing mapping and without hop-by-hop routing decisions.

A load-balancing router configured for routing data from a client to a selected load-balanced server among a plurality of servers in a network, comprising:

• a network interface that is coupled to the data network for receiving one or more packet flows therefrom;
• a processor;
• one or more stored sequences of instructions which, when executed by the processor,
• cause the processor to carry out the steps of:
• receiving a first packet of a client request at one of the load-balancing nodes in the network;
• storing information identifying a flow associated with the first packet, an identifier of an interface of that node on which the first packet arrived, and an outgoing interface identifier;
• receiving a first packet of a server reply at a last node associated with a selected server among the plurality of servers;
• receiving one or more subsequent packets of the client request;
• receiving a label value;
• storing the label value in a load balancing mapping at the last node that associates the label with the flow and interface identifying information;
• and
• forwarding the subsequent packets to the selected server on a route that is defined by the load-balancing mapping and without hop-by-hop routing decisions.