TCP Connection Scheduler in Single IP Address Cluster

A broadcast-based single IP cluster aims at being both scalable and available. However, existing systems can only employ static traffic assignment based on incoming packets. In this paper we propose FTCS, a new TCP connection dispatching mechanism that enables a single IP cluster to use more flexible load balancing algorithms. In this mechanism, one of the cluster nodes acts as a master node. A centralized connection scheduler runs on the master node in order to dispatch TCP connections to nodes of the clusters. Since connections are scheduled by a single scheduler, the master node is able to employ arbitrary scheduling algorithms. Once a TCP connection is established on a node, succeeding communication is handled without involving the master node. When the master node fails, one of the nodes takes over the role of the master node. Therefore the master node does not become a single point of failure. Benchmark results using SPECweb2005 Support benchmark show that a four-node Linux cluster using FTCS balances workloads well and successfully handles 13% more requests than the existing method, on average.