Net Dispatcher is a software router of TCP connections that supports load sharing across multiple TCP servers. It cosists of the Executor, an operating system kernel extension that supports fast IP packet forwarding, and a user level Manager process that controls it. The Manager implements a novel dynamic load-sharing algorithm for allocation of TCP connections among servers according to their real-time load and responsiveness. This algorithm produces weights that are used by the Executor to quickly select a server for each new connection request. This allocation method was shown to be higly efficient in real tests, for large Internet sites serving milliions of TCP connections per day. The Executor forwards client TCP packets to the servers without performing any TCP/Ip header translations. Outgoing server-to-client packets are not handled by NetDispatcher and can follow a separate network route to the clients. Depending on the workload traffic, the performance benefit of this half-connecitons method can be significant. Prototrypes of NetDispatcher were used to scale up several large and high-load Internet sites.
By: German Goldszmidt, and Guerney.D.H.Hunt
Published in: RC20853 in
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