Single IP Address Cluster for Internet Servers

Operating a cluster on a single IP address is required when the cluster is used to provide certain Internet services. This paper proposes SAPS, a new method to assign a single IP address to a cluster. The TCP/IP protocol is handled at a single node called the I/O server. The other nodes, called application nodes, provide the socket interface to applications. The I/O server and applications nodes are connected using a cluster-dedicated network, such as the Myrinet network. The key benefit of the proposed method is that the TCP/IP protocol does not care about congestion and packet loss in the cluster, which often happens if multiple nodes send packets to the bottleneck router. Instead, the cluster-dedicated network manages the packet congestion more efficiently than the TCP/IP protocol. The result of the bandwidth benchmark shows SAPS fully utilizes the bandwidth of the Gigabit Ethernet. The result of the SPEC Web benchmark shows SAPS handles 7.9% more requests than the existing method.